Hi Siddeq


The central meridian is imaginary meridian which serves as the starting point for measuring longitude of a celestial body,  it is the imaginary NS line bisecting the disk of a planet, satellite, etc., used as a reference, it is the center line of longitude for projection systems.A Central meridianis the center of a map projection where x = 0, and Central meridian can be any longitude line.

I hope that you find this helpful

Thankyou