Columns are vertical elements of the grid. They facilitate the arrangement of complex content, grouping information of the same sense to one section and dividing from others. The columns of the left are usually for images, ones on the right are for text. Columns are separated by gutters, providing whitespace between content sections.
The bigger number of columns increases the grid’s flexibility. Meanwhile, there are some widely spread grids of particular column quantity — the Bootsrap and 960 Grid.