All the components(code questions, assignment/case-study/project, timed test) which you have not attempted and went ahead in progress are called Skipped Components. Skipped components can be seen in the Home Page. You can go to anyone to complete that component in any later point in time.

As soon as you go on the next page without attempting any component on the current page, the component on that page goes to the 'skipped components' box. The box will contain all the skipped components in the box until you have attempted that component.