The Distinct function evaluates a formula across each record of a table. Distinct returns a one-column table that contains the results, with duplicate values removed.
Fields of the record currently being processed are available within the formula. You simply reference them by name as you would any other value. You can also reference control properties and other values from throughout your app. For more details, see the examples below and working with record scope.
Distinct( Table, Formula )
If you had an Employees table that contained a Department column, this function would list each unique department name in that column, no matter how many times each name appeared in that column: