MySQL GROUP by more than one field group usage detailed

The group by IS easily understood in the MySQL statement as a grouped query.
For example, select SUM (Score) from user group by name means to query each person's score sum
But, select SUM (Score) from the user group by item, sex?
Here is the test result.

The test data are as follows:

The results of the query are as follows:

According to the result analysis
Group by multiple fields is meant to be grouped by different combinations of each field
In this case item= mathematics sex=1 and item= Mathematics sex=2 will be divided into different groups to achieve the calculation and purpose