Ha ha, I’ll tell you anyway. ;*)
An attributive adjective is an adjective that’s used as an attribute of a noun, e.g. in “the stinky cheese”, “stinky” is an attribute of the cheese, so it’s an attributive adjective.
A predicative adjective is an adjective that’s used as a predicate of a noun, e.g. in “The cheese is stinky”, “stinky” is the predicate of “The cheese”, so it’s a predicative adjective. A copula is always required with a predicative adjective; in English, the copula is “be” (and its conjugations).
In the first case, it would be an cháis bhréan (cáis is feminine) and Tá an cháis bréan (in contrast to predicative nouns, most sentences with predicative adjectives use bí rather than is). Note that bréan could also be interpreted as “rotten”, so tufar could be a less ambiguous alternative.
In the second case, it would be an scannán scanrúil sin (“that awful film”) and Tá an scannán sin scanrúil (“That film is awful”).
But yes, you’ve got the difference between attributive adjectives and predicative adjectives.