Tab has several meanings you'll encounter:

1. A small flap or strip that sticks out from something, making it easier to grab, pull, or identify. The tabs on file folders help you find the right folder quickly. A pull tab on a soda can lets you open it without a tool. Tabs in your browser let you switch between different websites.
2. A bill for food or drinks at a restaurant. When your family finishes dinner, the waiter brings the tab showing what you owe. Someone might offer to pick up the tab, meaning they'll pay for everyone. If you order something at a restaurant and don't pay right away, you might ask the server to put it on your tab, keeping track of what you owe until you're ready to settle up.
3. The Tab key on a keyboard, which moves your cursor over to create neat columns or indents. Before computers, people used tab stops on typewriters to line up numbers or create organized lists. Today you might press Tab to move between fields when filling out an online form, or to indent the first line of a paragraph.