Security certificates are what show to users that your website is secure and it's safe for them to pass you personal information (for example their email address through a contact form).
More commonly people have security certificates for online shopping carts as they are taking credit card details from users online for an online stoire (https). However, since 2018 Google has given preference to secure sites in their search results so there's also a search results advantage to having SSL installed on your website.
Installing a Security Certificate
If you are using cPanel as your website control panel then in all likelehood you can use self signed certificates which cost nothing to install. However, you will have to renew these from time to time and here's how...
- Login yo your cPanel control panel (www.YourDomain.com/cPanel)
- Click on "SSL/TLS Status" (this will telkl you if a valid certificate is installed and if it has expired when it expired)
- Go Back to the cPanel if you need to install/renew an SSL cert
- Click on "Let's Encrypt™ SSL"
- Underneath "Issue a new certificate" click "Issue" and then when you are on the certificate issue page click "Issue" again to install a security certificate for the chosen domain
This will take a few moments to update but once done your site will be secure.