Quite can have two meanings. Firstly, the meaning of less than, but more than a little. It comes before a gradable adjective, adverb or verb, and before the aor an with a noun.
Quite cannot be used before comparatives. Other words such as rather, a bit or much are used instead.
There is one exception, however,quite can be used with better.
Secondly quite can mean completely, when used with non gradable adjectives, such as: certain, perfect, impossible, different, wrong, right and true.
Quite is also used in this way with verbs.
Rather is an adverb of degree, which is similar in meaning to quite but is used mainly with negative words or negative ideas.
Rather is usually put before the article when used with a noun, but if there is an adjective with the noun, it can be placed before or after a/an. It is not usually used with plural nouns