Definition - What does Modem Card mean?
A modem card is an internal type of modem that is plugged into the PCI slot of a PC motherboard. A modem is a communications device that allows a computer to send and receive data through telephone or cable lines.
Techopedia explains Modem Card
Most modern computers connect to a home network, a local area network or the Internet using an external modem or through an Ethernet port or a wireless device such as a USB dongle. However, during the early days of the Internet and before the advent of cable Internet and DSL connection, it was more common to use a modem card, which had to be added to a desktop computer manually, like a video card or sound card. This modem card used a landline telephone to connect to an Internet service provider, a technology known as a "dial-up connection."
The main problem with modem cards was speed, which was limited to 56 Kbps. Older modems used before the advent of the Internet were even slower and were measured in “baud” rate rather than in bits or bytes per second. Early 1400-baud modems were a standard for sending text to such destinations as online bulletin boards. The use of baud rate had since become obsolete, and the transmission speed of current modems is now measured in megabytes per second.