I use to travel between Lahore and Rawalpindi a lot on train. Every train has these compartments
1) Economy class
View attachment 441775
Has this seating arrangement.
Newer economy class has better finishing
View attachment 441779
You can catch any depending on your luck. Nothing is usually mentioned on ticket as to the train will have new built compartments or old.
2) Lower AC
There are two types of lower AC compartments in terms of seating arrangement. One is like buses with two seats on both sides and aisle in the middle
View attachment 441776
The other seating is same as economy, just has AC in it. Try your luck what you get.
3) AC Parlour
It has like usually seats facing with a table in the front. Like a restaurant
View attachment 441785
View attachment 441786
4) AC Sleeper.
It has compartments, each compartment has six berths, I travel in this mostly. Great for sleeping.
Corridor outside compartments
View attachment 441787
View attachment 441788
Inside the compartment
View attachment 441789
View attachment 441790
(Pictures taken from Google.)