Have you ever been to a site that your browser has announced to you that it’s not secure? That means that website did not have a valid SSL certificate!
A SSL certificate is a digital certificate of authenticity you can add to your website, and it will give your website an encrypted connection for your visitors. A website has a SSL certificate when it starts with “https” and has a padlock in the front.
You can click on the padlock to find out more information regarding the certificate as well.