The determiners are words like the, a, an, my, this, some, either, every, enough, several...
They come at the beginning of a noun phrase to determine whether a noun is known or unknown to the hearer, or how much or how many we are talking about, or to whom is something belonged, They consist of articles, possessives, demonstratives, quantifiers, and some words like other, such, only,...
BUT ajectives modify a noun, that is they talk about size, age, nationality, colour,material, shape, quality,..., like tall, old, iranian, brown, cotton, round, beautiful
Adjectives and determiners both come before nouns, but adjecives come after determiners if any. For example:
the young lady
some noisy students
my old white shoes
such a bad boy