Although not specifically a WordPress term, “mixed content” is a phrase you might run into when converting your WordPress site from HTTP to HTTPS. A mixed content error occurs when an HTTPS page includes resources delivered via HTTP.A mixed content error occurs when an HTTPS page includes resources delivered via HTTP. #WordPressClick To Tweet
There are two types of mixed content: passive and active. Passive content includes images, audio, and video. These are less dangerous because a man-in-the-middle attacker could only interact or modify those assets. Active content includes scripts, stylesheets, and iframes. There are the most dangerous because a bad guy could take control of the whole page or even the entire website.