Looking at the home screens, the primary difference you'll find is that in iOS 26 the background of the dock and the search option that sits in between the dock and the home screen icons are more transparent and have a sheen to the edges, whereas in iOS 18, these are slightly darker.

iOS 26 looks new and modern. And for once, how Apple describes it — liquid glass — makes sense: it’s a lot of layers of transparent elements overlapping and, in places, the animations are quite… liquidy. Menus and buttons will respond to your touch, with some of them coalescing around your finger and sometimes separating out into new menus.