The LFS book covers setting up networking by connecting to a LAN with a static IP address. There are other methods used to obtain an IP address and connect to a LAN and other networks (such as the Internet). The most popular methods (DHCP and PPP) are covered in this chapter.
DHCP stands for Dynamic Host Configuration Protocol. It is a protocol used by many sites to automatically provide information such as IP addresses, subnet masks and routing information to computers. If your network uses DHCP, you will need a DHCP client in order to connect to it.
PPP stands for Point-to-Point Protocol. It is a data link protocol commonly used for establishing authenticated IP connections over a phone line with a modem, or over radio waves with a cellular phone. There is also a variant (PPPoE) that works over Ethernet and is used by cable providers to authenticate the Internet connections.