|  | 3.1 | Basic LAN Devices
| 3.1.2 | LAN devices in a topology

Devices that connect directly to a network segment are referred to as hosts. These hosts include computers, both clients and servers, printers, scanners, and many other user devices. These devices provide the users with connection to the network, with which the users share, create, and obtain information. The host devices can exist without a network, but without the network we have greatly limited the hosts capabilities. This purpose of a LAN was discussed in Chapter 1.
Host devices are not part of any layer. They have a physical connection to the network media by having a network interface card (NIC) and the other OSI layers are performed in software inside the host. This means that they operate at all 7 layers of the OSI model. They perform the entire process of encapsulation and decapsulation to do their job of sending e-mails, printing reports, scanning pictures, or accessing databases. For those that are familiar with the inner workings of PCs, the PC itself may be thought of as a tiny network that connects the bus and expansion slots to the CPU, RAM, and ROM.
There are not standardized symbols within the networking industry for hosts, but they are usually fairly obvious to figure out. They bear a resemblance to the real device so that you are constantly reminded of that device.

The basic function of computers on the LAN is to provide the user with an almost limitless set of opportunities. Modern software, microelectronics, and a relatively small amount of money, enable you to run word processing, presentation, spreadsheet, and database programs. They also enable you to run a web browser, which gives you almost instant access to information via the World Wide Web. You can send e-mail, edit graphics, save information in databases, play games, and communicate with other computers around the world. The list of applications grows each day.