Types of computer modems
Below are the three available versions of a computer Modem that can be used in computers.
Internal modem that connects to a PCI slot inside a newer desktop computer or ISA slot on an older computer. The Internal Modem shown at the beginning of this document is an example of a PCI modem.
External computer modemExternal modem is located within a box and is hooked up externally to the computer, usually the Serial Ports or USB port.
Removable modem that is used with older laptops PCMCIA slot and is removed when you need the PCMCIA slot for another device, but are not planning on using the modem.