NASM--Apollo to the Moon--Guidance and Navigation

COMMAND MODULE MAIN DISPLAY CONSOLE
The main display console faces the three crew couches in the Apollo Command Module. It contains switches, dials, and meters used to control the spacecraft and monitor its performance. Displays and controls for related sub-systems are grouped together. Flight controls are on the left half of the console, systems controls are on the right. This console was removed from a command module simulator that was used for astronaut training.
Main Display Console of Command Module Columbia
GUIDANCE AND NAVIGATION
Apollo astronauts used three navigation systems to determine the proper flight paths to the Moon and back to Earth. These systems were used jointly or separately. Together they formed the Primary Guidance and Navigation System.
The inertial guidance system included accelerometers that sensed every change in the spacecraft's velocity or direction.
An onboard computer received data pertaining to the flight plan from the inertial system and from ground tracking stations on Earth. In addition, the astronauts could give the computer new information while in flight.