To look over something means to examine or review it, usually quickly or casually. When your teacher asks you to look over your essay before turning it in, she wants you to check for mistakes or things you might improve. When a doctor looks over your test results, he's reviewing them to understand your health.

The phrase suggests a less thorough examination than words like “study” or “scrutinize.” You might look over your notes before a quiz, scanning the main points without memorizing every detail. A coach might look over the team's practice schedule to make sure nothing conflicts.

Sometimes people use look over to mean they're literally looking across or beyond something, as in “I can look over the fence and see the neighbor's garden.” But more often, it means giving something your attention and consideration, even if briefly.

Notice the difference from “overlook”: to overlook something means to miss it or ignore it (often by accident), while to look over something means you're actively paying attention to it.