Each server provides a distinct network service: DNS resolves domain names, DHCP configures devices, file servers manage shared files, mail servers handle email, proxy servers mediate requests, and web servers deliver web content.
Server Functions
A server is hardware or software that provides a service to clients across a network. In A2.2 Network architecture, distinguish each server by its precise role, input, and output rather than saying only that it “stores or sends data.”
| Server | Function |
|---|---|
| DNS server | Converts a domain name such as example.com into its IP address and may cache results. |
| DHCP server | Automatically assigns clients an IP address, subnet mask, default gateway, and DNS server address, usually for a lease period. |
| File server | Centrally stores and manages shared files, access permissions, and backups for authorized users. |
| Mail server | Sends, receives, stores, and forwards email. SMTP sends or relays messages, while IMAP or POP3 retrieves them. |
| Proxy server | Acts as an intermediary. It can filter requests, restrict access, cache resources, log activity, and hide internal client IP addresses. |
| Web server | Responds to HTTP or HTTPS requests by sending or generating resources such as HTML, CSS, JavaScript, and images. |
A common misconception is that a DNS server gives a device its IP address. DNS resolves names; DHCP assigns network settings. A proxy also does not normally host the requested website: it forwards the client’s request to the appropriate external server.
Exam Technique
For an IB describe question, state what the server does and identify a relevant input or output. For example: “A DNS server receives a domain name and returns the corresponding IP address.” For a comparison, give a clear distinction, such as DHCP assigning an address while DNS resolves a name. Avoid vague claims such as “it connects computers” or “it manages the internet.”
