Attributive adjectives: are a part of noun phrase, for example: black cat - black is an attributive adjective here. Sentence: Yesterday a black cat crossed my path. More examples: green (wall), happy (girl), shiny (jewel), depressed (person), helpful (neighbor).
Predicative adjectives: are linked to noun or pronoun they modify, for example: smart (she is smart). Sentence: My best friend is very smart.
Absolute adjectives: they don't have a superlative, for example dead, pregnant. Nobody can be more or less dead/pregnant. She just is or don't. Sentence: My wife is pregnant.
If you need more examples write a comment :)