An SSL (Secure Socket Layer) Certificate ensures a safe exchange of information over the Internet. Any information exchanged between your website and a visitor will be protected against unauthorized access. A website that uses an SSL can be identified by the URL beginning with https://yourdomain.com with a security symbol.
HTTPS is the current leading standard for secure sites, and any webmaster hesitant to migrate is losing ground by the day, not to mention jeopardizing the trust of their users. Chrome flagging HTTP sites as unsecure is just one step in a long list of changes soon to come intended to better protect the privacy and security of sensitive information. There is simply no reason to delay HTTPS any longer.