The exclamation point is a punctuation mark used at the end of a sentence. It emphasizes strong emotions, particularly excitement, surprise, sarcasm, or enthusiasm.

It's shorthand that says, "I'm excited!"

Like other punctuation, an exclamation mark is intended to help readers grasp the meaning of your sentence. But these days, it's overused. Few of us believe that there's genuine excitement behind all the exclamation points floating around. Which means they're a crutch.