I once thought of a laptop as being a special-purpose computer, with miniaturized, slower components, a built-in screen/keyboard/mouse, and a battery, for 3x the price.
These days, the speed & price difference between desktop and laptop computers has gotten smaller. Battery life, screen size, and portability have improved to the point where laptops are useful for general-purpose use. I guess that's why laptop sales exceeded desktop sales 5 years ago.
Now I think of a desktop as being a special kind of computer, with important components missing (screen/keyboard/mouse/battery), that takes up too much space. In exchange for giving up all that important stuff, it's a bit cheaper.
"Computer" now means "laptop" to me.
(Ironically, the first laptop I ever bought is a server.)