This example uses the UNIQUE function, which is fully automatic. When UNIQUE is provided with the range B5:B16, which contains 12 values, it returns the 7 unique values seen in D5:D11.
UNIQUE is a dynamic function. If any data in B5:B16 changes, the output from UNIQUE will update immediately.
Dynamic source range
UNIQUE won't automatically adjust the source range if data is added or deleted. To feed UNIQUE a dynamic range that will automatically resize as needed, you can use an Excel Table, or create a dynamic named range with a formula.