Well this definitely isnt the official definition or anything...but this is what I think of:
Division 1 schools encompass most state schools (although a few are D2's and a very small fraction are D3's). They tend to be larger in comparison to the other D's. They are the "highest" aka most competitive on average for a few reasons: they can offer more and greater scholarships to players, as mentioned they are often state schools so they lower tuition and the greater general appeal of state schools. Also, lets face it; there are a lot less selective D1 schools than D3's from an academic sense... and that definitely has an impact on the type of student-athletes that they both can recruit and convince to come to their school.
D2's tend to be middle sized schools, sometimes state sometimes private. They ON AVERAGE tend not to be as good of schools academically as D1 and D3. They also have athletic scholarship capability and can attract D1 calaber players who might not want to warm the bench for 2 years before getting an opportunity.
D3 schools tend to be smaller, almost always private schools. Many focus primarily on academics, offering athletics for the pure enjoyement of the players in a more layed back sense. Others are extremely competitive. They are not allowed to offer athletic scholarhips in accordance with the academic focus. Many times they cannot attract the top caliber players either because of the seriousness of the program or because of rigid acceptance requirements.
There is also something called NAIA...I know they can give scholarships, but otherwise I do not know much about them.
This is a complete stereotype. Not all D1's are big public schools. Not all D2's are merely decent schools. Not all D3's are relaxed programs. The line is blurred...many D1 caliber players play D2 or D3 and so forth. This is meant simply as a guideline. I'll stop babbling now.
