Final answer:
The entrance used by most visitors to the White House is located in the Executive Office of the President, which includes security measures, the First Lady's offices, a movie theater, and a bomb shelter.
Step-by-step explanation:
The entrance where most visitors enter the White House is called the Executive Office of the President (EOP). Within this complex, there's a large security station equipped with measures for safety, including bomb-sniffing dogs. The area also houses important facilities such as the First Lady's offices, a private movie theater, and a secured bomb shelter to ensure the safety of the president and their family.
This area is part of a much larger configuration which includes the White House Office (WHO), where the president's personal staff of assistants and advisors work, and is exempt from Congress's oversight. Enhanced security and the presence of important offices like the First Lady's emphasize the importance and versatile functionality of this section of the White House complex.