You have the possibility of creating filters based on, for example, words contained in the email subject or body. Or maybe you want to create a filter based on the sender of the email. For instance you might want to directly delete mark as important the messages you receive from your manager.
As you see in the image below, Jane Example created a filter based on the topic “Digital Business Strategy”. With this filter each and every email containing that phrase skips the inbox, receives the custom label “Digital Business Strategy” (that Jane stylishly changed to be purple) and gets moved to that specific label. This filter helps to keep Jane’s inbox smaller and she has all the emails concerning the project “Digital Business Strategy” in one place.