About tabbed browsing

Tabbed browsing in Firefox lets you load Web pages in separate tabs of a single browser window, so you can jump between them quickly and easily.

Perhaps you´re reading a news story and want to follow an interesting link without losing your place in the original story. With tabbed browsing, you can do this without filling your desktop with new, unorganized browser windows.

See how much faster and easier it is to stay current with your favorite news, explore search results, and shop multiple Web sites at once. With new drag and drop reordering, you can also rearrange your tabs however you like.

Source: Mozilla.com