Just what is unschooling anyway?

We have been learning about homeschooling over the past few years and we have decided to try it for preschool and see how it goes...Through this I keep hearing the word "Unschooling" which at first seemed a little odd to me, But the more i read, the more it makes sense...perfect sense. You see, when a baby is first born he/she knows how to find the mama's breast, they learn to support their head, to sit up, to crawl, to eat, to walk, etc... children are natural born learners! How natural is it really to be put in a classroom with 25 -30 other children whom you don't know, and a teacher that you don't know as well. Everyone learns more from life itself, not from worksheets and tests and quizzes. Doing a worksheet on the stars, you learn a bit, but going out camping under the stars and learning about them with your family you gain more knowledge and retain in better because it becomes a memory :) Unschooling is the first form of learning...why not continue with it. We've already been doing it for 4 years now anyway! lol