You certainly have a laptop. Haven’t you? These are PCs that can be taken anywhere you go and can be used almost everywhere. A Desktop Computer typically comes at a lower price than a laptop, still Laptops beat desktops when it comes to mobility and Power Savings. Laptops are different to desktops at some level such as they dont have a power supply and they use a smaller Hard Disk Drive (usually 2.5″ in Size) also Laptops have smaller graphics processor than their Desktop Counterparts.
Here is an Infographic about Hardware of Laptops that will be beneficial for beginners in understanding what is a laptop made of.