BTX has up to seven expansion slots and can be up to 325.12 mm wide. MicroBTX has up to four expansion slots and can be up to 264.16 mm wide. PicoBTX has none or one expansion slot and can be up to...
A pico BTX is 10.5"x8" and only supports one or two expansions slots, designed for half-height or riser-card applications.A microBTX is 10.4"x10.5" (264x267mm) and it supports up to four expansion...
micro btx motherboards also called uBTX is an advanced an better form of motherboard than micro atx motherboards and it is manufactured by Intel and b stands for better.