When we want to talk about HOW MUCH of something there is, we use a Quantifier.
Common quantifiers include:
many
much
(a) few
(a) little
less
fewer
more
some
any
Grammatically speaking, quantifiers are a sub-group of determiners and we use them with nouns to describe the amount, extent or intensity of something.
Have you any rice?
There are some cookies in the jar.
Have you got many Facebook friends?
Quantifier or Adverbs of Degree?
Do not confuse quantifiers with adverbs of degree.
A quantifier comes in front of a noun. Here we have a quantifier talking about a noun:
Do you have much money?
But an adverb cannot modify a noun:
* Do you have very money?
* an asterisk denotes an ungrammatical sentence
Instead we can use an adverb to modify another adverb, for example:
He opened the box very carefully.
Useful Links
Determiners in English Grammar – the class of words which quantifiers belong to
Adverbs of Degree in English Grammar – using adverbs to talk about how much
Fewer vs Less – a common error; which to use, fewer or less