Pakistan Current Affairs

I am a mango person of Pakistan who lives in Punjab (A Province of Pakistan). Sorry I have to specify the the province because my dear readers there is a big difference between Sindh (Karachi) and Punjab electricity Situation. in Punjab there is a load shedding of 18 hours whereas in Karachi it is not more than 2 hours. Same as electricity, CNG is also short in punjab and only available 4 days a week whereas there is only 1 day load shedding in Karachi.
I Don't know politics but my question is why there is such difference. Is Punjab is not a part of Pakistan?
Why there is so many differences between Provinces.