EEB is a standard form factors for dual or multi processor motherboards defined by the Server System Infrastructure (SSI) Forum. SSI-EEB Form factor (width × depth) 12 × 13 in (305 × 330 mm)
microATX or uATX is another form factor standard for desktop motherboards.
The maximum size of a microATX motherboard is 9.6 × 9.6 in (244 × 244 mm)
One is for servers while the other is for desktop models. What model is the case you are inquiring about?