Where

The WHERE statement is used to filter the data by one or more conditions

For example to select all commits for a specific username

SELECT * FROM commits where name = "AmrDeveloper"
SELECT * FROM commits WHERE name contains "gmail"
SELECT * FROM branches WHERE is_head = "true"
SELECT * FROM branches WHERE name ends_with "master"
SELECT * FROM branches WHERE name contains "origin"

You can add Unary and Binary expressions, but you can use Aggregation functions inside the Where statement, because it calculated after the group by statement.