The SSL check will validate that a certificate is installed, it is valid, and who is the issuer of the certificate. It is important for websites that process sensitive data to secure data in transmission. This check isn't intended for users to validate a website is using SSL/TLS. Modern browsers today also validate and share SSL/TLS information. This check is good for website owners to validate the details of their certificate and what is being returned.

Secure Socket Layer (SSL) was created by Netscape and released to the public with version 2.0 in 1995. Version 1.0 was never publicly released and suffered from security flaws. Version 3.0 of SSL was released in 1996 and was the last major release of SSL. The big update in version 3.0 was the support for certificate-based authentication

In 1999 the Internet Engineering Task Force (IETF) took over development in SSL and released Transport Layer Security (TLS) 1.0. It is still common today for the padlock that appears in your address bar to be referred to as SSL and not TLS and the term SSL is acceptable to use professionally, though when discussing security it is common to discuss the version of TLS or to refer to it as SSL/TLS

Since the initial release of TLS 1.0 in 1999, IETF has released version 1.1, 1.2, and in 2018 version 1.3.

The SSL check will return data that falls into either the subject, issuer, or extension category. The subject is the domain being requested and is the only item in this category. The issuer has three items with the main item being the named of the organization the issued the certificate. The extension contains technical items such as keys.