What is the restricted area in basketball?

The restricted area in basketball is also known as the "paint" or the "key". It is a semi-circular zone underneath the basket with a radius of 4 feet. Any defender who enters this area and makes contact with an offensive player will be called for a blocking foul. The main purpose of this area is to protect offensive players from dangerous collisions while driving to the basket. Additionally, an offensive player may not stay in the restricted area for more than three seconds unless they are actively engaged in a shot attempt or have just received a pass.