Network (section 1)

What is a computer network?

A group of connected devices (called nodes) that can communicate and share resources like files, printers, or the internet.

What are examples of nodes in a network?

Personal computers, servers, routers/switches, and specialized devices like printers or smart TVs

What is a network address?

What is a hostname?

A human-readable label for a device, easier to remember than an IP address (e.g. Laptop).

What protocol uses network addresses to locate devices?

The Internet Protocol (IP).

What is a network host?

Any computer or device connected to a network that can send or receive data.

Give two examples of network hosts.

A Wi-Fi-connected laptop and a wireless printer.

What can a host do?

Provide services (server), use services (client), or both.

What’s the difference between an IP host and an Internet host?

An IP host uses Internet Protocol; an Internet host is an IP host that’s directly on the Internet.

How can a host get its IP address?

Manually (static), automatically with DHCP, or via IPv6 autoconfiguration.

What is a server?

A device that provides resources or services to clients (e.g., a web or file server).

What is a client?

A device or software that requests resources from a server.

What is a client-server relationship?

A client requests resources; a server provides them.

Example of a server-client interaction.

A phone (client) requests a web page from a web server (server).

What makes data-center servers powerful?

High CPU power, large RAM, and massive storage to serve millions of clients.

Give an example of a data-center service.

YouTube’s servers store and stream videos to users worldwide.

Do servers always have to be big machines?

No — even a laptop can act as a small server when sharing files locally.

How can two devices connect on the same network?

By using each other’s IP addresses.

What happens when you connect a device to Wi-Fi?

The router assigns it a unique IP address using DHCP.

What is a static IP address?

A manually set IP that doesn’t change, often used for servers (e.g., 192.168.1.50).

What is DHCP and what does it do?

Dynamic Host Configuration Protocol automatically assigns IPs when devices connect to a network.

What is stateless autoconfiguration used for?

In IPv6 networks, it lets hosts create their own addresses based on the network’s prefix.

What can be considered a resource in a network?

Files, videos, images, or other shared data/services.

How does a resource move across a network?

Clients request the resource, and servers deliver it.

What is the main purpose of a server?

To provide data, applications, or services to other devices.

What is the main purpose of a client?

To request data or services from a server.

Can a host act as both client and server?

Yes, depending on the task — e.g., sharing and downloading files.

What are the key features of data center servers?

High CPU power, large memory, and massive storage.

What do data center servers handle?

Millions of requests and users at once (like YouTube or Amazon).

Give an example of data center usage.

YouTube’s servers store and stream videos globally.

What happens when a phone requests a YouTube video?

The phone (client) asks, and YouTube’s server sends the video data.

What’s an example of a client-server interaction in a workplace?

A laptop (client) downloading a document from a company’s file server.

Do all servers have to be in a data center?

No, even a personal computer can act as a small local server.

Example of a home server.

A laptop sharing files over Wi-Fi acts as a local server.

Example of a home client.

A second laptop or phone downloading that shared file.

How can two devices communicate on the same network?

By using each other’s IP addresses (e.g., phone → laptop at 192.168.0.21).

What must devices share to connect via IP?

The same local network (Wi-Fi or LAN).

What does it mean if a website 'can’t be reached'?

The client device can’t locate or connect to the server’s IP address.

What allows two devices on the same Wi-Fi network to communicate?

Their unique IP addresses and shared network connection.

Why does each device need a unique IP on the same network?

To prevent conflicts so data reaches the correct destination.

What protocol assigns IP addresses automatically on most home networks?

DHCP (Dynamic Host Configuration Protocol).

What happens when a phone connects to Wi-Fi?

The router gives it a unique IP address so it can communicate with other devices.

Example of local IP communication.

Laptop → 192.168.0.21, Phone → 192.168.0.22; both can share files on the same network.

Can two devices still communicate if the Internet is down?

Yes, as long as they’re on the same local network.

What is the Internet in networking terms?

A vast network of interconnected smaller networks using the Internet Protocol.

What’s the difference between a local network and the Internet?

Local networks connect devices within a limited area; the Internet connects networks worldwide.

What is an Internet host?

Any IP host directly connected to the Internet.

Any IP host directly connected to the Internet.

A provider that sends or stores data for others.

Define 'client' in simple terms.

A receiver that requests or uses data from a server.

Can a computer perform both roles?

Yes — the same computer can act as a client or server depending on its task.

Why are hostnames used?

To give devices easy-to-remember names instead of IP numbers.

Example of a hostname vs. IP address.

Hostname: Person-Laptop; IP Address: 192.168.1.10.

When do hostnames usually change?

Rarely—after initial assignment they stay the same.

Example of a network resource request.

A browser asking a web server for a page

Example of a device acting as a server at home.

A laptop sharing media files over Wi-Fi.

Example of a device acting as a client at home.

phone streaming that shared media from the laptop.

What happens when your browser can’t reach a website?

The client can’t connect to or find the server’s IP address.

What ensures devices know where to send data?

Their unique network addresses and routing by the network protocols.

Summary of client-server relationship.

Servers provide; clients request. Both can exist on the same network or even the same device.