group by and order by which one wil come fisrst

 $users = DB::table('users')

            ->groupBy('age')

            ->orderBy('age', 'desc')

            ->get();

In SQL, when using both the GROUP BY and ORDER BY clauses in a query, the GROUP BY clause is applied before the ORDER BY clause.

The order of the clauses in a SQL query is as follows:

1. FROM: Specifies the table(s) from which to retrieve data.
2. WHERE: Filters the data based on specific conditions.
3. GROUP BY: Groups the rows based on one or more columns.
4. HAVING: Filters the grouped data based on conditions.
5. SELECT: Retrieves the columns or expressions to include in the result set.
6. ORDER BY: Sorts the result set based on one or more columns.
7. LIMIT: Specifies the number of rows to retrieve.