Micro ATX is one of the types of ATX that is used now. These are the two common form factors of desktops that are being used right now. ATX means Advanced Technology eXtended. This is the improved version of AT which is one of the first components used for desktops. Their shapes are a bit different from each other. The ATX is more rectangular while Micro ATX is considered to be squarer. From the name itself, you can also guess that this is smaller. The ATX will come with more expansion slots as compared to the Micro ATX though. This is something that you can consider when you are trying to decide which one you will get. The Micro ATX will also have fewer drive bays.
If you are familiar with the different things that are related to technology, you will know the difference between ATX and Micro ATX. These are common form factors that you can find whenever you purchase laptops or computers. ATX has a larger size as compared to the Micro ATX. If you would need more expansion slots, the ATX will be considered more ideal. You can also install the Micro ATX chassis in the ATX chassis if you need to do so. If you would try to do it the other way around, this will not be possible probably because the ATX is too large to fit the Micro ATX. When it comes to drive bays, the Micro ATX will have fewer ones.