Each 'row' is divided into 12 columns. You can decide how many 12ths your column should be, depending on the browsers
screen width (sm=Small, md=Medium, lg=Large, xl=Extra-large).
The first example below shows 12/12ths wide for very small screens and 6/12ths wide for small screens. Resize your browser to see how this works.
This example shows 12/12ths wide for very small screens, 6/12ths wide for small screens and 3/12ths wide for large screen sizes.
Column 1
Column 2
Column 3
Column 4
This example shows 12/12ths wide for very small screens, 4/12ths wide for small screens, 3/12ths for medium and 2/12ths for large.
Column 1
Column 2
Column 3
Column 4
Column 5
Column 6