Module 1 (NetAcad)

Host / End Device

Any computer or device connected to a network that is the source or destination of a message (e.g., PC, smartphone, server).

Client

A host that requests information or services from a server (e.g., your computer running a web browser).

Server

A host that provides information or services to clients (e.g., a web server hosting a website).

Peer-to-Peer (P2P) Network

A network where devices can act as both a client and a server simultaneously. Common in small homes and offices.

Intermediary Devices

Devices that connect end devices and ensure data flows across the network (e.g., Routers, Switches, Firewalls).

Network Media

The physical channel through which data travels.

Copper Wires

Data as electrical impulses.

Fiber-Optic Cable

Data as pulses of light.

Wireless

Data as electromagnetic waves.

Topology Diagram

A visual map of a network.

Physical Topology

Shows the physical location of devices and cables.

Logical Topology

Shows the IP addressing scheme, ports, and how data logically flows.

LAN (Local Area Network)

A network in a small geographical area (e.g., a single home, office, or campus).

WAN (Wide Area Network)

A network that spans a large geographical area, connecting multiple LANs.

The Internet

A global "network of networks".

Intranet

A private collection of LANs and WANs belonging to a single organization, accessible only internally.

Extranet

A secure extension of an intranet that allows external partners (like suppliers or customers) to access specific resources.

Home/SOHO Options

Cable, DSL (Digital Subscriber Line), Cellular, Satellite, Dial-up.

Business Options

Dedicated Leased Lines, Metro Ethernet, Business DSL.

Converged Network

A single network infrastructure that carries multiple types of traffic (data, voice, and video).

Fault Tolerance

The ability of a network to continue operating despite the failure of a link or device, often through redundancy (multiple paths).

Scalability

The ability of a network to expand and support new users and applications without degrading performance for existing users.

Quality of Service (QoS)

A mechanism to manage network traffic and prioritize certain types of data (like video calls) over less time-sensitive data (like email) to ensure a quality user experience.

Security

The protection of network infrastructure and the information transmitted over it. It is based on three principles

Confidentiality

Only authorized users can read the data.

Integrity

The data has not been altered in transit.

Availability

Authorized users have timely and reliable access to data.

BYOD (Bring Your Own Device)

The practice of employees using their personal devices to access corporate networks and data.

Cloud Computing

Accessing software, storage, and computing power over the internet instead of from a local server or computer. Types include Public, Private, Hybrid, and Community clouds.

Online Collaboration

Tools that allow people to work together remotely (e.g., Cisco WebEx).

Powerline Networking

Using existing electrical wiring in a home to transmit network data.

Threats

Viruses/Worms, Spyware/Adware, Zero-Day Attacks, Denial of Service (DoS) attacks, Data Interception.

Solutions

Antivirus/Antispyware, Firewall, Access Control Lists (ACL), Intrusion Prevention Systems (IPS), and Virtual Private Networks (VPN).