Views are specific to the tables for which they are created. When you create a table, three predefined views are created by default: Personal, Mobile and Summary.
If you change your own personal view, it will have no effect on other users' personal views. By contrast, if you change any other view for which you have access, it will affect all users with access to it.
A user's personal view will not be overwritten with the default view for his team when the default view is modified. If a user is using the team default view and makes changes, then those changes are saved to the user's personal view. The user's personal view will not be changed if changes are subsequently made to the team default view, which enables users to have their own personal view and a team default view.
The mobile view shows only one field by default: Created By. The Mobile view cannot be deleted, but it can be edited. Mobile views are designed to be used when a user is viewing the system on a mobile device or when logged in as an ADA compliant interface.
The summary view shows only two fields by default: Record ID and Creator Login. As with the mobile view, the summary view cannot be deleted but it can be edited. The summary view is the default view until an admin applies a different default view for a team.