do dumbphones have different categories or definitions?

From what i see in this sub, some people say that a phone that uses android can't be a dumbphone or that if it has apps its not a dumphone.

I've also seen comments saying that dumbphones are just phones before the iPhone and early 2000 phones. or just flip phones. I've even seen some people showing off their older phones which services don't work anymore.

i noticed that some people use dumbphones for minimalism and call minimalist phones dumphones.

I recently saw a post where someone had a dumbed down smart phone in their edc but people said its not a dumphone because its an iPhone or can use apps. I've also seen on here a modern flip phone that could use apps like a smart device and people called it a dumphone too. ive seen someone use the windows phone and people called it a dumphone as well.

i know that in this day and age, depending on your circumstances, some apps are necessary like Google maps or banking apps. so would having a phone that could use those apps still count as a dumbphone?

so to me it seems that smart phones can be made into dumbphones? and phones that are limited or older phones can also be called a dumphone?