Mixed content refers to a webpage where the initial HTML content is loaded over a secure HTTPS connection, but other resources (such as images, videos, stylesheets, scripts) are then loaded over an insecure HTTP connection. This is called mixed content because both HTTP and HTTPS content are being loaded to display the same page, and the initial request was secure over HTTPS. Modern browsers display warnings about this type of content to indicate to the user that this page contains insecure resources.