Here are two works of art, that I think explain very clearly the second ammendment.
In the first, it shows the good guys on the left. The armed militia (people)defending itself from a standing army of a government.
The second , I beleive is very interesting.
It shows a "special" Militia. Those militia members were called Klansmen. They are all armed... It aslo shows a group of Blacks on the right. They are armed also.
In between them is a constable of the law, trying to keep peace. Once he leaves,,the Blacks become vunerable to hate. Without weapons, guns ,(look closely) Bayonetts in theis case,, they would be most definiatly violated.
The second ammendment guarentees us ALLLLL to the right to keep and bear arms. Not just "special", "approved", or "typed".