Many current modems are also capable of sending and receiving faxes.
Many high end modems are also capable of voice mail. Internal modems are boards which are literally plugged into the motherboard inside the computer case. The boards may be short and occupy only half of a typical motherboard slot or long and occupy a full motherboard slot. A typical internal modem usually includes an on-board speaker, which is software adjustable for monitoring the progress of calls, and two standard telephone jacks for connecting a telephone line and a telephone instrument. External modems are boards which are mounted in a separate case and connected to a computer's communications port by a cable.