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Glossary

What Is an SSL Certificate

An SSL certificate verifies a website's identity and enables encrypted connections. Plain-English definition for business owners.

Definition

An SSL certificate (technically TLS certificate, but SSL remains the common name) is a small data file installed on a web server that does two things: it verifies that the website genuinely belongs to the organisation claiming to own it, and it enables an encrypted connection between the server and the visitor's browser. When a site has a valid SSL certificate, you see a padlock icon in the browser address bar and the URL begins with "https" rather than "http". The certificate is issued by a trusted Certificate Authority that has verified the site owner's identity.

Why It Matters

An SSL certificate is a baseline requirement for any website today. Without one, data travelling between your site and your visitors is sent in plain text. Form submissions, login credentials, and payment details can all be intercepted by anyone on the same network. Browsers now actively warn visitors when a site lacks SSL, displaying “Not Secure” warnings that drive people away. Google also uses HTTPS as a ranking signal, meaning a site without SSL may rank lower in search results. For e-commerce or any site handling personal data, operating without an SSL certificate is both a security risk and a trust problem.

Example

A small business launches an online booking form without an SSL certificate. Customers filling in the form notice a “Not Secure” warning in their browser’s address bar and abandon the page, worried about entering their phone number and email address. After installing a free SSL certificate through their hosting provider, the warning disappears, the padlock appears, and form completion rates increase noticeably within the first week. SSL certificates are what make HTTPS possible, and they are the most visible layer of encryption your visitors will ever see. More definitions are in the glossary.

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