What is a PC without a tower called?

Could you please clarify for me what is meant by a "PC without a tower"? Typically, a personal computer, or PC, refers to a desktop computer that has a central processing unit, or CPU, housed within a tower-like case. If a PC does not have a tower, it could potentially be referring to a different type of computer altogether, such as a laptop, tablet, or all-in-one desktop. Is there a specific type of computer you're asking about, or are you seeking a general understanding of how computers can differ in their form factors?