What is "mixed content" in the context of HTTPS security?

Mixed content occurs when a secure HTTPS page loads resources (like images, scripts, or stylesheets) over an insecure HTTP connection. This compromises the security of the entire page because the insecure resources can be intercepted, modified, or exploited, even though the main page is served securely. Browsers often display warnings or block insecure content to protect users, which can degrade user experience and site functionality. The goal is to ensure all resources on an HTTPS page are also loaded via HTTPS. The other options describe common web page structures (text and images, multiple authors, various content types) that are not inherently security issues related to HTTPS.