This is where you select possible sources for your paper. And we don’t mean you have to read every single line of the article. That would be silly. Find the abstract and read it. It’ll give you a good idea of the article’s contents so you can make an informed decision to include it (or not) with the other articles you have collected. We recommend selecting twice the number you’re required to have for the paper (if you need 10 sources, select 20) because you’re going to be eliminating some of your sources later.
Getting the sources you need from the initial research you’ve already done makes the process a bit more efficient. And it means you won’t have to go back later to do it again.