DISTINCT (column) Returns a one-column table that contains the distinct values from the specified column. In other words, duplicate values are removed and only unique values are returned.
This function cannot be used to Return values into a cell or column on a worksheet; rather, you nest the DISTINCT function within a formula, to get a list of distinct values that can be passed to another function and then counted, summed, or used for other operations.
Syntax
DISTINCT(column)
Parameters
Column – The column from which unique values are to be returned. Or, an expression that returns a column.
Return Value
A column of unique values. The results of DISTINCT are affected by the current filter context. For example, if you use the formula in the following example to create a measure, the results would change whenever the table was filtered to show only a particular region or a time period.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference