Major buses and their features

A bus is a parallel circuit that connects the major components of a computer, allowing the transfer of electric impulses form one connected component to any other.

• VESA  -   Video Electronics Standard Association:  
                         32 bit, relied on the 486 processor to function
• ISA     -   Industry Standard Architecture:
                         8 bit or 16 bit with width 8 or 16 bits. 8.3 MHz speed, 7.9 or 15.9 bandwidth accordingly.
• EISA   -   Extended Industry Standard Architecture:
                         32 bits, 8.3 MHz, 31.8 bandwidth,  the attempt to compete with IBM's MCA
• PCI    -   Peripheral Component Interconnect:
                         32 bits, 33 MHz, 127.2 bandwidth
• PCI-X -   Up to 133 MHz bus speed, 64 bits bandwidth, 1GB/sec throughput
• AGP   -   Accelerated Graphics Port:
                         32 bits, 66 MHz, 254,3 bandwidth