Does hyphenation create a prefix?

When two words are hyphenated do they always become one word? Or does it depend on why you use the hyphen?

For example 'four-wheeled carts'. Has 'four' become a prefix or is the purpose of the hyphen to simply imply the relationship between the two words?

Cheers

Answer

No. Hyphenating two adjectives creates a compound adjective, composed of two distinct words, connected by a hyphen for clarity.

From wikipedia:

A compound modifier (also called a compound adjective, phrasal adjective, or adjectival phrase) is a compound of two or more attributive words: That is, more than one word that together modify a noun.