Determiner

A determiner is a word such as an article, possessive, demonstrative that helps to identify things, or a quantifier that indicates how much or how many things are being referred to.

Classes of Determiners
There are a number of classes of determiners:

the, a, an
 * Definite and Indefinite articles

this, that, these, those
 * Demonstratives

my, your, his, her, its, our, their
 * Possessives

a few, a little, much, many, a lot of, most, some, any, enough
 * Quantifiers

one, twenty, thirty, etc.
 * Numbers

all, both, half, either, every, neither, each
 * Distributives

other, another
 * Difference words

Which, what, whose
 * Question words

which, whose
 * Defining words

There are also pre-determiners which go before determiners, such as articles these include: such, what, half, rather and quite.