A view is a particular way of displaying the same underlying data - as a table, a kanban board, a calendar, a gallery or a chart. The data stays in one place in the database; the view just determines how whoever needs it is looking at it right now.
A typical example: a sales team tracks jobs through a kanban view by stage (inquiry → quote → in progress), while finance sees the same data as a table sorted by due date. Both sides work with the same records, just filtered and sorted differently - with no risk of the data drifting apart.
Views can also be filtered (show only jobs for a specific client), sorted, and used as a source for reporting - a summary over a filtered view (like "open jobs this month") can be calculated the same way as over the whole database.
Related: Reporting via view columns and formulas, Views, A data model that grows with the team.