Joomla Force SSL is a Joomla feature to activate the SSL Certificate on your Joomla website.
SSL stands for Secure Sockets Layer, it is a security protocol that transmits private data across your Joomla site to the encrypted format. Accordingly, connections to/within your site will be on the secure https protocol instead of the standard http prefix.
Your site really needs SSL Certificate?
If you own an eCommerce or business website, SSL Certificate is nearly a must to protect your critical data. See the Further Knowledge section for the detailed appraisal.