Glossary

A/B Testing

What It Actually Means A/B testing shows two versions of something to different visitors at random and measures which produces more of the outcome you want. It is the closest thing marketing has to an experiment, and its appeal is obvious: instead of arguing about whether the green button works better, find out. The Problem Most Businesses Have You probably...

Agile

What It Actually Means Agile is building software in short cycles, showing working results frequently, and adjusting as you learn, rather than planning everything in advance and delivering once at the end. The reasoning is sound and worth stating plainly: nobody knows exactly what they need at the start. Not you, and not the people building it. Long detailed plans...

AI Agent

What It Actually Means An AI agent is given a goal rather than a script, and can take actions to pursue it: calling systems, reading records, deciding what to do next based on what it finds. The distinction from a chatbot is doing versus saying. A chatbot answers. An agent looks up the order, checks the stock, issues the refund...

AI Hallucination

What It Actually Means A hallucination is when an AI system produces something fluent, confident and false. An invented citation, a policy that does not exist, a customer record it has no basis for, a legal case nobody ever tried. The word is unhelpful because it suggests a malfunction, something that occasionally goes wrong and could be fixed. That is...

API

What It Actually Means An API is a defined way for one piece of software to talk to another: a set of requests it will accept and answers it will give. The everyday version is that it is how your systems can share information without a person copying it between them. Your website sends an enquiry to your CRM. Your...

API Key

What It Actually Means An API key is a string identifying your system to somebody else’s. You present it with each request and their system decides what you are permitted to do. It is a credential. That is the whole point and it is routinely forgotten, because a key looks like configuration rather than like a password, and gets handled...

Audit Trail

What It Actually Means An audit trail is a record of who did what, to which record, and when. Not what the data says now, but how it came to say it. The distinction between a log and an audit trail is worth holding onto. A log is written for engineers, to diagnose faults, and it is usually rotated away...

Authentication

What It Actually Means Authentication is proving who someone is. It is the login: the point at which an anonymous visitor becomes a known person. It answers exactly one question, and it is important to be precise about which one, because the confusion between this and what comes next causes real problems. Authentication establishes identity. It says nothing whatsoever about...

Authorisation

What It Actually Means Authorisation decides what a known user is allowed to do. It follows authentication, which established who they are. The two get discussed as one topic and they behave very differently. Authentication happens once, at a single point, at the start of a session. Authorisation has to happen continuously, at every point where the system shows information...

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Backlink

What It Actually Means A backlink is a link from another website to yours. Search engines treat them as evidence: if credible sites reference you, you are probably worth showing. It remains among the strongest factors in whether a site can compete for commercially valuable terms, and it is the part of SEO that cannot be manufactured by working harder...

Backlog

What It Actually Means The backlog is the ordered list of everything that might be built and has not been yet: features, fixes, improvements, ideas. The important word is ordered. A backlog is not a wish list, it is a queue, and the order is the real roadmap regardless of what any roadmap document says. Whatever sits at the top...

Backup

What It Actually Means A backup is a copy of your data held somewhere separate, kept so that you can get back to a known good state after something goes wrong. The word does a lot of quiet damage, because it makes people think about the copy. The copy is the easy part and it is not what protects you....

Bounce Rate

What It Actually Means Bounce rate is the share of visits where somebody arrived and left without a second interaction. The important thing to know before discussing it is that the definition changed. In older analytics a bounce was a single-page visit, however long they stayed. In GA4 it is the inverse of engagement, where an engaged session means more...

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Caching

What It Actually Means Caching stores the result of work so the same work does not have to be done again. A page is built once and served many times. A database query runs once and its answer is reused. It is usually the single highest-return performance improvement available, because most systems spend most of their time repeatedly producing identical...

Canonical URL

What It Actually Means A canonical tag tells search engines which address is the real one when the same content is reachable at several. That happens more than people expect, usually without anyone intending it. A page might be reachable with and without www, over http and https, with and without a trailing slash, with tracking parameters appended, with filters...

CDN

What It Actually Means A content delivery network keeps copies of your site’s files on servers in many locations, so a visitor downloads from one nearby rather than from wherever your server happens to be. Distance costs time. A request travelling to another continent and back adds delay that no amount of server performance removes, because the limit is physics...

Cost and Scope

Change Request

What It Actually Means A change request is a written note of something outside the agreed scope, with a price and a time impact attached, that you approve or decline before any work starts. That is the whole mechanism. Its value is entirely in the ordering: priced first, built second. Reverse those and it stops being a change request and...

Chatbot

What It Actually Means A chatbot holds a conversation through text. The category covers two things that behave nothing alike. Scripted bots follow a decision tree someone drew. Press 1 for accounts. They handle exactly what was anticipated and collapse the moment a question is phrased unexpectedly. Most people’s dislike of chatbots was earned by these. Model-based bots use a...

CI/CD

What It Actually Means Two connected ideas usually spoken as one. Continuous integration is automatically checking every change as it is made: running the tests, checking style, looking for known security problems in dependencies. If a check fails, the change does not proceed. Continuous delivery or deployment is automatically taking changes that passed and putting them live, or making them...

CLI (Command-Line Interface)

What It Actually Means A command-line interface is a text prompt where instructions are typed rather than clicked. The terminal window developers spend a great deal of time in. To anyone outside software it looks like a step backwards, and its persistence is not nostalgia. It survives because of one property that graphical interfaces do not have. Why It Has...

Client Portal

What It Actually Means A client portal is a secure area where your customers log in to see their information and do things: view documents, check progress, submit requests, approve work, pay invoices. It is distinguished from a dashboard by audience. A portal faces outward, to clients. A dashboard faces inward, to your team. They are frequently confused in briefs,...

Client-Side Rendering

What It Actually Means Client-side rendering means the server sends a mostly empty page plus the application code, and the browser builds what you see. The first response contains very little. The browser downloads the code, runs it, requests the data, and assembles the page. Everything after that is fast, because navigation updates what is already loaded rather than fetching...

Cloud Hosting

What It Actually Means Cloud hosting means renting computing capacity from a provider who runs the hardware, with the ability to add or remove capacity quickly and pay for what you use. Amazon Web Services, Google Cloud and Microsoft Azure are the large ones. There are smaller providers offering a similar model with considerably less complexity. The distinction from traditional...

Code Review

What It Actually Means Code review is another developer reading a change before it goes live, and saying so if something is wrong. Mechanically it usually happens through a pull request: the change is proposed, someone else reads it, comments, and approves or asks for adjustments. Nothing reaches the live system until that has happened. Why It Matters To You...

Compliance

What It Actually Means Compliance is meeting the rules that apply to you, and being able to show it. Those are two separate jobs, and the second is where the time goes. Most businesses are broadly doing the right things. What they cannot do quickly is produce evidence of it on request, which is why compliance feels expensive out of...

Component

What It Actually Means A component is a self-contained piece of an interface that can be used wherever it is needed: a button, a date picker, a customer card, a data table. It is built once, with its appearance and behaviour together, and then reused. Modern interfaces are assembled from components rather than each page being built from scratch. Why...

Container

What It Actually Means A container packages an application together with everything it needs to run: the runtime, the libraries, the configuration. The result behaves the same wherever it is started. Docker is the name most people encounter. The problem it addresses is the oldest complaint in software: it worked on the developer’s machine and not on the server, because...

Content Marketing

What It Actually Means Content marketing is publishing material genuinely useful to the people you want as customers, so they find you, trust you, and eventually buy. It works. It also takes considerably longer and requires considerably more from you than the version usually sold, which is a monthly quota of articles produced by someone with no knowledge of your...

Context Window

What It Actually Means The context window is how much text a model can consider in a single request: your instruction, any material you supply, the conversation so far, and the answer it produces, all counted together. Exceed it and something has to be dropped. This is why a long conversation with an AI assistant starts forgetting the beginning, and...

Controller

What It Actually Means A controller is the part of an application that receives an incoming request, works out what needs to happen, and returns a response. Somebody submits a form. The controller takes what was sent, checks it is valid, asks the rest of the system to do the work, and decides what the user sees next. It coordinates...

Conversion Rate

What It Actually Means Conversion rate is the proportion of visitors who do the thing you wanted: enquire, buy, book, sign up. Simple arithmetic, and both numbers in it are chosen by whoever produces the report, which is why the same underlying performance can be presented as excellent or poor without anybody lying. How The Same Month Becomes Two Different...

Core Web Vitals

What They Actually Are Three measurements Google uses to describe how a page feels to use. Largest Contentful Paint is how long until the main content appears. Under 2.5 seconds is the target. This is what people mean by loading speed. Interaction to Next Paint is how quickly the page responds when somebody taps or clicks. Under 200 milliseconds. It...

CORS

What It Actually Means CORS is a browser rule governing whether code running on one website is allowed to call an API belonging to another. By default the browser refuses. Without that default, any site you visited could quietly issue requests to your bank, your email or your company systems using your logged-in session, and read the answers. The restriction...

Crawl Budget

What It Actually Means Crawl budget is how much attention a search engine is willing to spend on your site: how many pages it fetches, and how often it comes back. It is not infinite and it is not equal across sites. It scales roughly with how important the site appears to be, which in practice means how much external...

CRM

What It Actually Means A CRM holds the record of your relationships with customers and prospects: who they are, what has been discussed, what is outstanding, what stage a deal is at. The intent is a single place where the state of every relationship is visible, so it does not live in one person’s inbox and memory. The Way They...

CRUD

What It Actually Means CRUD stands for create, read, update and delete: the four things you can do to a record. Add a customer, look one up, change their details, remove them. Almost every business application is these four operations applied to whatever records the business cares about, wrapped in rules about who may do which. Developers use the term...

Cross-Site Request Forgery (CSRF)

What It Actually Means Cross-site request forgery makes a logged-in user’s browser perform an action they did not intend, on a site they are legitimately signed into. The mechanism relies on something browsers do helpfully: they attach your cookies for a site to any request going to that site, regardless of which page triggered it. So a page on an...

CTA (Call to Action)

What It Actually Means A call to action is the thing you are asking a visitor to do: get in touch, book a call, download something, buy. It is usually discussed as a button, and it is really a decision about what you are asking for and whether the visitor is ready to give it. The Two Common Failures Too...

CTR (Click-Through Rate)

What It Actually Means Click-through rate is the proportion of people who saw something and clicked it. Clicks divided by impressions. It applies to search listings, ads, emails, anything that gets shown and might be clicked. It measures one specific thing well: how appealing the thing was at the moment of seeing it. What It Does Not Measure Whether the...

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Dashboard

What It Actually Means A dashboard presents the current state of something in one view: numbers, charts, statuses, whatever is needed to see how things stand without opening five systems. It faces inward, to your team, which is what distinguishes it from a client portal. Why Most Get Abandoned The pattern is reliable. A dashboard is commissioned, delivered, admired, looked...

Data Breach

What It Actually Means A personal data breach is any security failure that leads to personal data being destroyed, lost, altered, disclosed or accessed without authorisation. Accidental counts. Internal counts. That definition is wider than most people assume, and the gap causes real problems, because businesses look for an attacker and conclude nothing happened. An email with client details sent...

Database

What It Actually Means A database is where an application’s information is stored: customers, orders, records, history. Structured so it can be found, changed and related to other information reliably. Most business systems use a relational database, where data lives in tables with defined relationships between them. Customers have orders, orders have lines, lines refer to products. The structure enforces...

Cost and Scope

Database Migration

What It Actually Means Database migration covers two quite different jobs that share a name, and confusing them causes real problems. The first is a schema migration: a small, routine, versioned change to the structure of a database that ships alongside a code change. Adding a column, adding an index. These happen constantly on any active system and are unremarkable....

Dependency

What It Actually Means A dependency is a piece of code your application uses that somebody else wrote and maintains: a payment library, a PDF generator, a date handler, an image processor. Modern software is assembled far more than it is written. A typical business application might directly use thirty or forty components, and those use others, and by the...

Deployment

What It Actually Means Deployment is moving new code from where it was written to where customers use it. That sounds procedural and it is one of the more revealing things about how a system is built, because deployment is where all the assumptions get tested at once. The Question Worth Asking How long does it take to get a...

Cost and Scope

Digital Transformation

What It Actually Means Digital transformation is changing how a business operates because software makes a different way of working possible. Not putting the existing process on a screen. Changing the process. The distinction is the whole thing. Taking a paper form and making it a web form is digitisation, and it is often worth doing. Digital transformation is realising...

Disaster Recovery

What It Actually Means Disaster recovery is the plan for getting the business working again after something takes it out: hardware failure, a provider outage, ransomware, a deletion nobody meant to make. Backups are one component. Disaster recovery is the whole sequence, including who decides, who acts, what order things come back in, and what the business does meanwhile. The...

DNS

What It Actually Means DNS is the system that turns a name people can remember into the address of an actual machine. Somebody types your domain, DNS answers with where to send them. It is worth understanding at one level of detail, because DNS problems are common, they present as several different symptoms, and they are frequently misdiagnosed as something...

Domain Name

What It Actually Means A domain name is the address people type to reach you. You do not own it outright; you register it for a period and keep it as long as you keep renewing. It is worth thinking of as a lease on the most important piece of property your business has online, because everything else depends on...

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Embeddings

What It Actually Means An embedding turns a piece of text into a list of numbers that represents its meaning. Passages about similar things produce similar numbers, even when they share no vocabulary at all. That last point is the whole value. Traditional search matches words: ask about “staff leaving” and a document about “employee attrition” is invisible, because no...

Encryption

What It Actually Means Encryption scrambles data so it is unreadable without the key. That is the whole idea, and it comes in two situations that get conflated constantly. In transit protects data moving between places: your browser and the website, the application and its database, one service and another. This is what the padlock in the address bar indicates,...

End-to-End Testing

What It Actually Means An end-to-end test drives the whole system the way a person would: open the site, log in, add an item, check out, confirm the order appears. Automated, through a real browser, against a running application. It is the only kind of test that verifies the thing your customer actually does, all the way through, which is...

Endpoint

What It Actually Means An endpoint is a single address in an API that performs one specific operation: fetch a customer, create an order, update a status. An API is the whole set. An endpoint is one thing in it. When a developer says the endpoint is returning an error, they mean one specific operation rather than the whole integration....

Environment Variable

What It Actually Means An environment variable is a setting supplied to an application from outside it, rather than written into the code. The same application then behaves differently depending on where it is running. On a developer’s machine it connects to a local database; in production it connects to the real one; and the code is identical in both....

ERP

What It Actually Means Enterprise resource planning is one system running the core operational functions of a business: finance, purchasing, stock, orders, sometimes manufacturing and payroll. The idea is a single source of truth. A sale updates stock, triggers purchasing, posts to the ledger and appears in reporting, without anyone re-entering it anywhere. Why It Is A Bigger Decision Than...

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Fine-Tuning

What It Actually Means Fine-tuning takes an existing model and trains it further on examples you provide, adjusting its behaviour toward the patterns in those examples. The phrase people use is “training the AI on our data”, and that phrasing is the source of most of the confusion, because it implies the model will then know your data. That is...

Firewall

What It Actually Means A firewall controls which network traffic is allowed to reach a system. It works from rules: this kind of connection from these places is permitted, everything else is refused. The mental model most people carry is a wall around the building, and it is a reasonable one as far as it goes. The limitation is that...

Framework

What It Actually Means A framework is a foundation providing the structure and common machinery an application needs: handling web requests, talking to a database, managing users, organising code. Building without one means writing all of that yourself, badly, and maintaining it forever. Every serious project uses one. Framework Or Library A library is something your code calls when it...

Funnel

What It Actually Means A funnel describes the stages somebody passes through from first hearing of you to buying: aware, interested, considering, deciding, purchased. Fewer people remain at each stage, which is where the shape and the name come from. Its practical value is diagnostic. When enquiries are down, the funnel tells you where rather than merely that. Fewer people...

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