DeepNews analyzes all the articles you read and distills out the topics that interest you.
The set of these topics then forms the basis for presenting you with new news items appropriate to your interests.
From time to time, or at your request, i.e. when you scroll down in the ForYou view, for example, DeepNews goes through your topics and sees if there are any new matching news items for them. Roughly speaking, DeepNews weights topics higher if your interest was not just temporary, but if you have read an article on the topic more than once.
Note: You can delete temporary topics from your profile via '...'.