wat is the difference between...........

Society Religion & Philosophy
1

assalamoalikum :jhanda:

can u tell me the difference between higri and eisvee!!!

                             AND

also i don’t understand when ppl talk about or say for example its 1422 a.d. islamic yr and stuff… i don’t understand how they work this out.

also sorry about this… i was searching a website about the incoming of the proimised hazrat imam mehdi (elihissalatuawasalam) and i came across this word, wat does it mean> (Khatam-e-Vilayat-e-Muhammadia)