A typo is a mistake made while typing or writing, usually a small error like hitting the wrong key, leaving out a letter, or accidentally repeating a word. The word is short for typographical error. When you're typing quickly and write “teh” instead of “the,” that's a typo. When you accidentally capitalize a letter in the middle of a word or forget to add a space between two words, those are typos too.

Typos happen to everyone, even professional writers and careful students. Your finger might slip on the keyboard, or you might be thinking faster than you're typing. Most typos are easy to spot and fix, which is why proofreading your work matters. A few small typos in a text message to a friend usually don't matter much, but typos in a book report, a poster for the school play, or a letter to your grandmother can make your work look careless.

Before computers, fixing typos meant retyping entire pages. Now, spell-checkers catch many typos automatically, though they can't catch everything. If you type “form” when you meant “from,” both words are spelled correctly, so the computer won't notice the mistake. That's why reading through your work yourself remains important, even with helpful technology.