Adjectives, words that function to modify or specify another word.

In the context of verbs-that's action words- i might say 'I walked carefully down the path beneath grandma's window'-the adjective there is 'carefully', so you know this wasn't a leisurely stroll to grandmas house, but a treacherous overgrown path, or i don't want grandma to know im coming for that sweet sweet inheritance, or grandma thinks the geneva conventions are 'cucked-ass yankee shit', or maybe i just want my favorite old war criminal to enjoy her nap without interruption.

So in the context of nouns, thats people places and things, 'terrible old men'

Refers to men (that's a noun!)

But only the ones who are both terrible and old.

So, for example, a nine year old boy who rapes the family dog for shock value would not be in this group-he certainly sounds terrible, but nine years is not very old. We arent talking about him.

And a very old man who isn't terrible, maybe the 90 year old guy who helped liberate dachau, came home, researched vaccines for the rest of his career then retired to his hobby of whittling toys for the neighborhood children. OP isn't talking about him. He's not ruining anything. He sounds great. More of that guy please.

So, 'the quick brown fox' would mean we're talking about the fox who is quick and brown, not the quick red fox, or the other brown fox with the busted leg and the opium habit.

And when we say the quick brown fox jumped over the lazy dog, you know we're talking about the lazy dog, and not the border collie who compulsively herds everything never seems to sleep and has so much energy it really seems to be a problem! Were talking about a fox (the quick brown one) jumping over a dog (the lazy one).

And now you know what adjectives are!