Footer in WordPress can refer to two different things. Most often, it refers to widget areas that appear as a row of short columns positioned below your main content area. The most popular number of footers is 3, but the number can vary from theme to theme. Some themes support more than one row of footers.

Footer content is managed in Appearance/Widgets. Contact information and navigation menus often appear in footers.

Footer can also mean a content band at the very bottom of a website page that is built in to your theme for decorative purposes, which may include text promoting WordPress or the theme author, as well as a copyright notice. In WordPress.com sites it may not be possible to edit this band.

Some themes for self-hosted WordPress also include such a band, especially if there is a paid version of the theme with more features (removal of the promotional text is often promoted as one of the benefits of the paid version). It is usually possible to remove the text from these bands, though it may require editing theme files, which should only be done by someone knowledgeable.