SSL is an acronym for Secure Socket Layer, and this certificate provides a secure encrypted connection between the server and your Internet browser.
SSL certificates were created in 1994 as a response to concerns about insufficient Internet security. They have not been used for a long time, but now they are becoming standard, especially on sites where people enter sensitive data (personal and identification data, debit/credit card number, login data, etc.)
It is possible to have an SSL certificate free of charge in the form of the Let’s Encrypt certificate, or alternatively Wildcard SSL, Rapid SSL or Thawte SSL, which are paid certificates.
Then, in your browser, your site security will look like this: