Difference between top level Work Item and Backlog Work Item in Azure DevOps

Question

What is the difference between Work Item at the top level and Work Item in Backlog? Top level Work Items seem to have no use in sprints etc. Are they for a completely different use not related to product development?

Creating a Work Item from the Backlog screen makes it visible in Work Items at the top.

Creating a Work Item at the top (clicking on Work Items, then new Work Item) does not make it visible in the Backlog list of Work Items.

Answer 1

I checked on Scrum process and on the backlog you can add only these two Work Item Types:

If you add them on top level, they will also appear here. However if you on top level you will add different types of WIT they will not appear in Backlog.