A view is a stored query. You can select data from a view to return the results of the query. You can also think of a view as a virtual table. A view can be created from one or more tables and can contain all or just some of the rows from one or more tables.
Views can be important for allowing certain users to have access to only specific fields in a table. If you had sensitive data in some of the columns and you didn't want everyone to be able to view that data, then you could provide them with the view instead. Also, you can use a view to make column names more intuitive by using column aliases in the view definition. You could also summarize data in a view to generate reports.
