Computer form factor
In computer technology, the form factor is an indication of size and mounting options of a component, which is used in a computer. This standardization various components can be easily assembled and replaced. Often the term " form factor " nothing else is meant than the term " format ", sometimes as much as with "standard" or "specification". Although so far the word ' factor "is somewhat misleading, the term is often used as a literal translation from English ( form factor ).
Form factors describe, for example, printed circuit boards, disk drives and power supplies. For PC motherboards ( mainboards ) mounting heights of electronic components and the number, location and size of the mounting holes, for example, size, set.
Motherboard
Motherboards that have a smaller size than ATX, are often summarized under the collective term Small Form Factor.
Bolded: specified dimensions ( not rounded)