I cloud Drive

iOS & iPadOS

Can someone give a detailed overview of how I cloud Drive works? I know you still have the iCloud settings within the Settings app on the iPhone.But I hear that I cloud Drive is more like dropbox now. So how do you add our view content to Or from iCloud?
So say for instance if I want to access a note I created on my iPad, and I want to view it on my iPhone via iCloud drive, how would I do that?