An adjective is a 'describing' word giving more information about the object signified.
- Attributive adjectives are part of the noun phrase headed by the noun they modify; for example, happy is an attributive adjective in "happy people".
- Predicative adjectives are linked to the noun or pronoun they modify; for example, happy is a predicate adjective in "they are happy" and in "that made me happy."
- Absolute adjectives do not belong to a larger construction, and typically modify either the subject of a sentence or whatever noun or pronoun they are closest to; for example, happy is an absolute adjective in "The boy, happy with his lollipop, did not look where he was going." [Link: Wikipedia]
I was taught verbs create action and pace while adjectives bloat sentences and drain tension; that adjectives should be replaced by verbs. For example, "the stallion galloped" is better than "the stallion ran fast." Mark Twin despised adjectives ("If you catch an adjective, kill it!") while Ernest Hemingway considered them a "weak writer's crutch" and Stephen King warned "the road to hell is paved with adjectives."
Writing style matters and some writers use adjectives very well. But the general rule is: limit word bloat by replacing adjectives strong verbs.