English speakers usually call their refrigerator "the fridge". For example:

I have some beers in the fridge. You want one?

The word "refrigerator" sounds a bit formal. You say "refrigerator" when you're talking about it as a machine. For example, when you're calling a repairman:

Can someone come out and take a look at my refrigerator? It's not staying cool like it's supposed to.