Contact list has the following columns:
Person shows a contact's full name received from a channel. It can be edited if you open a person profile. Status shows the type of contact's importance for your company. There are 3 options: Visitor, Lead, Customer. Channel shows a messaging app that a contact used for getting in touch. Owner shows a user who is responsible for a contact. Team shows an owner's team. Last activity shows a time of the lastest case.
Each column in Contacts can be sorted.