ATX is the form factor.
MB is ATX form factor.
Embedded Compact Extended Form Factor
The NLX form factor has a riser card on the edge of the motherboard.
form factor tell about the purity of sine wave
laptop expansion memory form factor
The purpose of the small form factor is to make a desktop computer appear smaller in size. It is a computer form factor which can be used for this purpose.
Form factor represents the feature placement, size and general layout in a mother board. The AT form factor is considered to be the largest and the oldest.
For sure, it is the Motherboard, the Power supply, and the Chassis that determines the form factor of a computer.
The AT form factor
The full AT form factor measures 12" x 13.8"
Small Form Factor committee was created in 1990.