Your college application essays are an important part of your college application. Your essays are your chance to show the college admissions board who you are!
Personal Statement

This is the first essay you will need to write. There are a number of ways you can approach this; for example, by discussing an experience you had or circumstances that shaped you. Your personal statement should be just that; personal. It should give the reader an understanding of your character. Your essay should be original, not generic. If an essay starts out: “I was a member of the drama club which showed me the value of team spirit . . . ” the admission’s board will basically recite the rest of your essay without even reading it. This kind of essay is not going to stand out. You’re the “voice” that makes the essay good. Your essay must also have sharp focus and details that appeal to the senses. Those details will differentiate your essay, and thus application, from another.
College-Specific Essays
Many universities will ask you to write additional essays, often on why you wish to attend that university. They may also ask you to write more creative essays that show another side of you.
A final note regarding application essays...
Don’t start your essays too late! College admissions boards understand when they're reading a hurriedly written essay. 
Get someone to edit the essay with you for content, flow, and voice. These are important as they bring power to a short personal essay, and make it stand out.