Mini ATX, FlexATX and Extended ATX (see PC motherboards). THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

As can be evidenced from the motherboard size chart above, there's quite a dramatic difference in scale between Mini-ITX and MicroATX, with more of a subtle difference when comparing ATX and EATX ...

RGB gaming PCs are plentiful, but few look as impressive as this white and purple gaming PC ... case provides plenty of room for the Gigabyte ATX motherboard, an Aorus Elite AX model with support ...