Autocorrect is a computer feature that automatically changes what you type when it thinks you've made a mistake. When you type “teh” on your phone or tablet, autocorrect notices the error and switches it to “the” without you having to fix it yourself.

The feature works by comparing what you type against a dictionary of known words. When it spots something that doesn't match, it makes its best guess about what you meant. Sometimes autocorrect is incredibly helpful: it catches genuine typos and saves you from embarrassing spelling mistakes in texts or emails.

But autocorrect isn't perfect. It can create hilarious or frustrating problems when it “corrects” something you actually meant to type, like changing a friend's unusual name into a common word, or turning your carefully chosen vocabulary word into something completely different. You might type a place name and watch it transform into nonsense. These mistakes happen because autocorrect doesn't always understand context: it can't always tell whether you meant to type “their,” “there,” or “they're” based on grammar alone.

Autocorrect is a useful tool, but it can't replace your own careful attention when you write.