What is the function of the DISTINCT keyword in SQL queries?

The keyword DISTINCT in SQL is used to select unique values from a column or set of columns. It excludes duplicates in the result set.

For example, if a table has multiple records with the same value in the "city" column, the query

SELECT DISTINCT city FROM customers;

will return a list of unique cities without repetitions.

This is useful when you need to obtain a list of unique elements rather than all records.