When something is exaggerated, it has been made to seem bigger, better, worse, or more dramatic than it actually is. If your friend says “I've told you a million times,” that claim is exaggerated: they haven't literally told you a million times, but they're emphasizing their point. When someone describes a fish they caught as “absolutely enormous” when it was really just medium-sized, that description is exaggerated.

To exaggerate means to stretch the truth in this way, and an exaggeration is the statement itself. If you say “This backpack weighs a ton,” that's an exaggeration: it's heavy, but it doesn't actually weigh 2,000 pounds.

People exaggerate for different reasons. Sometimes it makes a story more entertaining: “The line at the amusement park was so long it wrapped around the building three times!” Sometimes people exaggerate their accomplishments to impress others, or exaggerate problems to get more sympathy or attention.

There's a difference between exaggerating for effect (which everyone does sometimes when telling stories) and exaggerating so much that people stop believing you. If you constantly make exaggerated claims about everything, people learn to doubt what you say, even when you're telling the truth.