An abbreviation is a shortened form of a word or phrase. Instead of writing “doctor” every time, you can write “Dr.” Instead of “United States of America,” you can write “USA.” Abbreviations save time and space, which matters when you're taking quick notes, writing an address on an envelope, or texting a friend.

Some abbreviations use just the first few letters of a word, like “apt.” for apartment or “Ave.” for Avenue. Others, called acronyms, use the first letter of each word in a phrase: NASA stands for National Aeronautics and Space Administration, and SCUBA stands for self-contained underwater breathing apparatus.

Notice that many abbreviations include periods, especially in formal writing (Mr., Inc., etc.), though some don't (TV, OK, FAQ). The rules can vary, which sometimes confuses even adults.

You encounter abbreviations constantly: on street signs (St., Blvd., Rd.), in measurements (ft., lb., oz.), in titles (Dr., Prof., Rev.), and throughout your schoolwork (p. for page, vs. for versus). Learning common abbreviations helps you read faster and write more efficiently. When you create your own abbreviations in notes, just make sure you'll remember what they mean when you review them later.