The format of something is the way it's organized, arranged, or presented. A book's format might be hardcover or paperback, large print or regular size. A report's format includes how you arrange the title, paragraphs, and spacing on the page. When your teacher asks you to submit homework in a specific format, she means following certain rules about fonts, margins, and how to organize your work.

The word also works as a verb: to format a document means to set up its structure and appearance. You might format an essay with double spacing and page numbers, or format a poster with colorful headings and images arranged just right.

In technology, format has special meanings too. A file format describes how information is stored digitally: MP3 for music, JPEG for photos, PDF for documents that look the same on any computer. When you format a hard drive or USB stick, you're preparing it to store data by erasing everything and setting up a fresh organizational system.

Different formats serve different purposes. A formal letter follows a specific format with the date at the top and a greeting, while a text message uses an informal format. Comic books use a format of panels and speech bubbles, while novels use continuous paragraphs. Choosing the right format helps your audience understand and enjoy what you're sharing.