This circle is called the center circle.
The center circle on an NBA regulation basketball court has a circumference of 37.7 feet (37 feet 8.4 inches).
A basketball game starts in the center of the court with a tip off.
The diameter of the center court circle in the NBA and WNBA is 12 feet. In FIBA (the International Basketball Federation) the circle is slightly smaller with a diameter of 11.81 feet.
its called half court
Seats in a basketball court are called bleachers.
with a jumpball at center court
It's usually the Center.
The Schottenstein Center