Why are SSL certificates necessary?
Safeguard your customers' sensitive data from prying eyes - whether it be passwords, credit card details or other sensitive information
Make certain that you are transmitting information to the trusted servers and not impersonators trying to steal information.
SSL certificate is to provide authentication to a website. Visitors will trust your website more when they see visual cues like a lock icon or a green bar that vouches for your identidy and integrity.
Google has decided to flag the websites which do not have an SSL/TLS Certificate installed on their website. Which can also help to rank better on Google search and other search engines.
If you accept online payments, your website must be PCI compliant. Having an SSL certificate installed is one of the 12 primary requirements set by the payment card industry (PCI).