This table below summarizes different bus types.

Bus Name	Bus Width	PCs Used In
ISA	8-bit	8088-386
ISA	16-bit	286-Pentium
MCA	16/32-bit	IBM's PS/2 386-486
EISA	32-bit	386-486
VESA	32-bit	486
PCI	32/64-bit	Pentium