Does anyone know what kind of cheese they use at mexican restaurants?

There are two really popular ones, guess depending where you go.

They are either:

Cotija or,

queso fresco.

Cotija cheese is a bit dry in texture, slightly salty.

Queso fresco's texture feels slightly moist.

manchengo cheese. you can usually find it in the refrigerated section of your grocery store near the refrigerated salsa and tortillas.

it is the same as feta cheese but contains less salt

queso fresco, if you can't find it in the store feta has similar taste/texture

its what's used in Mexico too, only Americans load Mexican food with cheddar and sour cream

Queso poblano also, nata

It is probably fresh farmer's cheese in the USA.

cheddar or colby

CHEDDAR!!!!

si queso fresco - crumbly

it's simply called "mexican cheese"

but yes, it had a very crumbly consistency and it's very good!

edit: yes, it's called queso fresco as well