Sticky column (or also known as a sticky sidebar) is an interactive method to redirect more attention to the content inside the column. 

To set one up, here are the steps:

1. Build the columns in the page editor. For example we're turning the left (smaller) column sticky:
   
   
   
   
2. Edit Section Styles, then choose Vertical Alignment Top
   
3. Once columns are ready, find Sticky Column in the modules list:
   
   
   
   
4. Drag-and-drop the Sticky Column module into the column you wish to turn sticky
   
   
5. Done.