What
The SSL certificate (Secure Socket Layer) changes the http to https, the S standing for ‘secure’.
Developed by Netscape in 1994, the SSL protocol uses a cryptographic system that establishes an encrypted link between a server and a client, preventing third-parties from reading or modifying any sensitive data transferred between them.
Why
SSL jumbles up the data from the server to the system.
It keeps internet connections secure and prevents people from gaining access to information transferred between two systems.
How
Most SSL certificates are activated by the host although you can still buy 3rd party certificates and install them yourself.
Once you have SSL installed you need to add code to your htaccess to force the redirection. On this website it looks like this:
The code forces any http request to https
RewriteCond %{HTTP_HOST} ^forestpathways\.co\.uk [NC]
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://forestpathways.co.uk/$1 [R,L]