When you compare things, you consider them and discover the differences or similarities between them.

If you compare one person or thing to another, you say that they are like the other person or thing.

If one thing compares favourably with another, it is better than the other thing. If it compares unfavourably, it is worse than the other thing.

If you say that something does not compare with something else, you mean that it is much worse.

If you describe something as beyond compare, you mean that it is extremely good or extremely great.