Well,I’m not a Center expert but what i know is that this frequency is used by plane in transit over a airspace, depending on the country’s or zone, work for planes above FL180-240. After takeoff you switch to DEPARTURE(if open) then DEPARTURE when you reach the altitude will tell you to contact CENTER untill you get in APPROACH frequency.
anyway @Brandon_Sandstrom and @Hayden_Hutchens are more precise than me.
This link may help give you some good context as to what the original irl purpose of center is and may help you to understand the functions better when a member of the the IFATC team tells you. I mean this is a sim.
@Rodney_Buckland… @Pilotmaster2129. Just passing thru. ATC of primary interest. Will always weigh in when the thirst for knowledge is evident.
Regards Friends, Max