Large bag.. 15.6 laptop can easily fit inside.. Normal padding... There is no strap to hold the laptop inside the compartment... The back of the bag is not straight.. Its bent towards the inside... Because of which the bag is not balanced. If you keep the bag on a table it topples over to the front. Except for the laptop partition, the partitions inside are thin without any padding. The shoulder straps are strong and bag is very comfortable to carry.