HOW MANY LITERS IS THIS BACKBACK ?

If it's listed as 2380 cubic inches this would be approximately 39 liters.

How many pockets does this backpack have?

There are two side pockets (one mesh, one that zips closed), two front pockets (one is larger with sections inside) and then the large main section that has smaller sections inside as well

Are the dimensions airline carry-on compatible? What are the dimensions?

Definitely airline compatible. It’s a bit heavy and bulky for a backpack because it has laptop protection, but it can fit a lot and def fit under seat or in overhead.

I used this to move around with an 8lb Laptop, 4 composition size books, 2-3 text books with appx. 400pages each, a charger for the laptop weighing another 2lbs. Gaming controller. Stationary. And it never gave up, the straps are extremely strong. I've been loyal to this brand for the past 10-12 years, because the bags last forever.