Qué, cuál, and cuánto are Spanish interrogative adjectives. An adjective is a word that modifies a noun, and interrogative means questioning, so interrogative adjectives are adjectives used to ask the questions what, which, and how much/many.
Cuyo is a relative adjective that means whose, of whom, or of which. Like other Spanish adjectives, cuyo agrees with the noun it modifies in gender and number. Cuyo is used to indicate the noun who or which is the object of the clause that follows.