So columns are the foundation ofalmost any Bootstrap layout. They’re going to take your design and divide itinto vertical groups, that way you don’t have to design your own responsivegrid. You’re going to just use whatever Bootstrap gives you.
Now when you docreate a column, you’re also going to create a gutter, and the gutters bydefault are going to be 30 pixels wide. That means that you’re going to have 15pixels on each side of the column. So what you do to create a column is youtake an element and you add a class to that element inside a row, and theyshould follow this format.
It should say col-, and then asize, which is two letters, we’ll talk about them in a minute, and then anotherdash, and then the number of columns that you want this layout to span, or thiselement that you’re creating. So the size means when the column will convert intowhatever you specified in the span into a single column layout. In other words,it’s going to stack into a single column layout at a specific break point. Thebreak point is going to be determined.