While it can sometimes function similarly to an adjective, it doesn't fit the strict definition. Here's why:
* Adjectives modify nouns: They describe or provide more information about a noun.
* Determiners specify nouns: They tell us which noun we're talking about or how much/many of the noun.
Examples:
* Adjective: "The beautiful sunset" - "Beautiful" describes the sunset.
* Determiner: "All the students" - "All" specifies which students we're talking about (all of them).
"All" is not a traditional adjective because it doesn't directly describe a quality or characteristic. Instead, it quantifies the noun (it indicates the total amount).