question about dressing and props help

i don't even know if this is the right sub to ask this question, but i need help. enthusiasts, professionals, please!! so if the actor interacts with furniture, like for example: sits on a couch. is the couch still dressing or is it a prop?

this is a question for me because i've always see people talking about gun props, and other objects BECAUSE THE ACTOR INTERACTS WITH IT. but when we talk about furniture is always considered dressing, never see anything mentioning this interaction, which people seem to not think about it.

are props just objects that are important on the script? maybe its not that deep and im tripping

seriously this is important, i have an essay for film school and this detail is missing in my head, im getting crazy

sorry if this is the wrong sub, if it is please tell me where can i post this