Css Grids and Columns. Not sure about this

Question

Could someone explain the difference between 12, 16 and 24 column grids?

I've always just designed websites to a set width and never bothered with columns but for the life of me I cannot get my head round why there are these columns and how to distinguish which type of column layout I would need.

Answer 1

Did you read the docs on the 960.gs site? They explain the difference between the 12, 16 and 24 grid columns like this:

The 12-column grid is divided into portions that are 60 pixels wide. The 16-column grid consists of 40 pixel increments. Each column has 10 pixels of margin on the left and right, which create 20 pixel wide gutters between columns.