How does django.db connection pass raw SQL queries through Psycopg2?

When using psycopg2 as the database connector specified in a DATABASES constant in settings.py, how do raw SQL queries get handled? When you use django.db.connection and cursor.execute(), does it use Django's classes to handle things, or psycopg2s?

Here's an example constant:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'webdev',
        'USER': 'someone',
        'PASSWORD': 'soopersekrit',
        'HOST': 'localhost',
        'PORT': '5432',
    }
}

and example raw query setup:

    from django.db import connection
    with connection.cursor() as cursor:
        sql_statement = f'''
        UPDATE cart c SET 
            apples = {apples_count},
        WHERE c.id = {table_row_pk}
        '''
        cursor.execute(sql=sql_statement)