The homepage of a website. If you type Mailchimp.com into your browser, the page that appears is our index page. Sometimes people refer to pages that collect all of a website’s links, images, or headlines into a single page as an index page like a book. Both are correct, which just makes things more confusing. If you’re talking with a web developer, they probably mean the homepage when talking about index pages. Ask for clarification if you’re not sure.