The CNR, or Communication and Network Riser, is a type of slot that supports audio, modem, USB and Local Area Network cards. This slot is highly recommended for any user building a large number of computers because the cards costs a lot lesser than
the standard PCI or ISA cards.
4.ISA
Nowadays, ISA or Industry Standard Architecture slot is becoming outdated and can not be found on all motherboard anymore., It is advisable to purchase a new motherboard with no ISA slots and additional PCI slots unless you have old ISA cards that need to be used
5.PCI
The PCI slot or Peripheral Component Interconnec, allows for all types of cards. This is also the most widely and commonly used slot today.