What is an SSL certificate?
The thing that puts the padlock and the "https" in your address. It encrypts data between your site and its visitors.
An SSL certificate (the modern protocol is TLS) enables the secure, encrypted connection between your website and the people visiting it: the padlock icon and the https:// at the start of your address.
What it does
It encrypts the data travelling between a visitor’s browser and your server, so things like contact-form details or passwords can’t be read in transit. It also confirms that visitors are connecting to the real you, not an impostor.
Why sites need one
- Trust. Browsers flag sites without it as “Not secure”, a quiet conversion-killer.
- SEO. HTTPS is a confirmed (if small) Google ranking signal; see SEO.
- Function. Many modern browser features require a secure connection.
The practical bit
SSL certificates are free and automatic on many modern hosting platforms. Services like Let’s Encrypt let hosts issue and renew them for you. If your site shows “Not secure,” fix it before you ask visitors to trust a form, checkout or login.