What is the difference between *larder* and *pantry*? Is it size? Or content?

I found very similar definitions for both terms, something like 

> 
> a room/place in which food is stored. 
> 
> 
> 

Which of the words is better for a separate room next to the kitchen, and which is better for a food-dedicated cupboard? Or even for a separate house for food storage, like they used to have in castles?