Computer Networks

Introduction to Computer Networks

A computer network is a set of computers connected together for the purpose of sharing resources. The most common resource shared today is a connection to the Internet. Other shared resources can include a printer or a file server.

Topics Covered

• Network Architecture
• Network Topologies
• OSI Model
• TCP/IP Model
• Network Devices
• Routing
• Network Security

Network Architecture

Network architecture refers to the layout of the network, including the hardware, software, connectivity, communication protocols, and mode of transmission, such as wired or wireless.

• Client-Server Architecture
• Peer-to-Peer Architecture

Network Topologies

Network topology is the arrangement of the various elements (links, nodes, etc.) of a computer network. Here are some common topologies:

• Bus Topology
• Star Topology
• Ring Topology
• Mesh Topology
• Hybrid Topology

OSI Model

The OSI (Open Systems Interconnection) model is a conceptual framework used to understand network interactions in seven layers:

• Physical Layer
• Data Link Layer
• Network Layer
• Transport Layer
• Session Layer
• Presentation Layer
• Application Layer

TCP/IP Model

The TCP/IP model is a concise version of the OSI model, consisting of four layers:

• Network Interface Layer
• Internet Layer
• Transport Layer
• Application Layer

Network Devices

Network devices or networking hardware are physical devices that mediate data traffic in a computer network. Here are some common devices:

• Router
• Switch
• Hub
• Bridge
• Modem
• Access Point

Routing

Routing is the process of selecting a path for traffic in a network. Here are some key concepts:

• Static Routing
• Dynamic Routing
• Routing Algorithms
• Routing Protocols

Network Security

Network security involves measures taken to protect data during their transmission. Here are some key concepts:

• Firewalls
• Encryption
• Virtual Private Networks (VPNs)
• Intrusion Detection Systems (IDS)
• Intrusion Prevention Systems (IPS)