It's a 12 column (col) grid, so a 'col-lg-6' takes up half of the page. 'col-offset-3' adds a 3 column margin on the left, effectively centering the element. h

It's a 12 column (col) grid, so a 'col-lg-6' takes up half of the page. 'col-offset-3' adds a 3 column margin on the left, effectively centering the element. http://getbootstrap.com/css/#grid http://getbootstrap.com/css/#grid