Apple Macintosh Performa 6400 Series - Manual (Page 140)

Installing a communication card
This section contains instructions for installing an Ethernet or internal
modem card in the communication slot in your computer. You use an
Ethernet card to communicate with other computers through a local area
network. For example, in businesses, it is what enables more than one
computer to print on a shared printer and to access documents on a central,
shared server.
Note: Using a modem is not the same as being connected to a local area
network. If you have an internal modem and the appropriate software that
makes use of it, you already have access to online services. You do not need
an Ethernet card unless you need to connect your computer to other
computers in an Ethernet network. For more information about connecting to
an Ethernet network, see “Connecting to an Ethernet Network” in Chapter 8.
140 Chapter 9