There are a lot of different machines, devices, and media that make up our networks. Let’s talk about three of the most common:
■ Workstations
■ Servers
■ Hosts
Workstations
Workstations are often seriously powerful computers that run more than one central processing unit (CPU) and whose resources are available to other users on the network to access when needed. Workstations are often employed as systems that end users use on a daily basis. Don’t confuse workstations with client machines, which can be workstations but not always. People often use the terms workstation and client interchangeably. In colloquial terms, this isn’t a big deal; we all do it. But technically speaking, they are different. A client machine is any device on the network that can ask for access to resources like a printer or other hosts from a server or powerful workstation.
Servers
Servers are also powerful computers. They get their name because they truly are “at the service” of the network and run specialized software known as the network operating system to maintain and control the network.
In a good design that optimizes the network’s performance, servers are highly specialized and are there to handle one important labor-intensive job. This is not to say that a single server can’t do many jobs, but more often than not, you’ll get better performance if you dedicate a server to a single task. Here’s a list of common dedicated servers:
- File Server : Stores and dispenses fi les
- Mail Server :The network’s post office; handles email functions
- Print Server : Manages printers on the network
- Web Server : Manages web-based activities by running Hypertext Transfer Protocol (HTTP) for storing web content and accessing web pages
- Fax Server : The “memo maker” that sends and receives paperless faxes over the network
- Application Server : Manages network applications
- Telephony Server : Handles the call center and call routing and can be thought of as a sophisticated network answering machine
- Proxy Server : Handles tasks in the place of other machines on the network, particularly an Internet connection.
Hosts
This can be kind of confusing because when people refer to hosts, they really can be referring to almost any type of networking devices—including workstations and servers. But if you dig a bit deeper, you’ll find that usually this term comes up when people are talking about resources and jobs that have to do with Transmission Control Protocol/Internet Protocol (TCP/IP). The scope of possible machines and devices is so broad because, in TCP/ IP-speak, host means any network device with an IP address. Yes, you’ll hear IT professionals throw this term around pretty loosely; for the Network+ exam, stick to the definition being network devices, including workstations and servers, with IP addresses.
Here’s a bit of background: The name host harks back to the Jurassic period of networking when those dinosaurs known as mainframes were the only intelligent devices able to roam the network. These were called hosts whether they had TCP/IP functionality or not. In that bygone age, everything else in the network-scape was referred to as dumb terminals because only mainframes—hosts—were given IP addresses. Another fossilized term from way back then is gateways, which was used to talk about any Layer 3 machines like routers. We still use these terms today, but they’ve evolved a bit to refer to the many intelligent devices populating our present-day networks, each of which has an IP address. This is exactly the reason you hear host used so broadly.