Also known as a modal window.

An area on a webpage which loads overtop of the content, but is not a pop-up.

It is an overlay that prevents the user from clicking anywhere else on the screen -- other than on the modal.

A user doesn't need to perform any action to open the modal. It automatically opens in the same window as the webpage.

A modal is different from a pop-up in that a pop-up appears in a separate window, once the user has landed on the page. A pop-up can also be closed, where as a modal only disappears when the user has clicked or interacted with it.