Grid
Container, row and 12 responsive columns. Breakpoints: sm (576), md (768), lg (992), xl (1200).
Live demo
col-md-4
col-md-4
col-md-4
col-6
col-md-3
col-md-3
col-6
col-md-3
col-md-3
col-6
col-md-3
col-md-3
col-6
col-md-3
col-md-3
Code
<div class="container">
<div class="row">
<div class="col-md-4">Left column</div>
<div class="col-md-4">Middle column</div>
<div class="col-md-4">Right column</div>
</div>
</div>
Tip: below a breakpoint, columns stack vertically. For example col-md-4 becomes a single column under 768px.