Computer Networks

1. Types of Computer Networks
   1. Personal Area Networks (PAN)
      1. Characteristics
         1. Short-range connectivity
         2. Often used for personal devices
      2. Examples
         1. Bluetooth networks
         2. Infrared communication
      3. Usage Scenarios
         1. Connecting a smartphone to a headset
         2. Synchronizing data between devices
   2. Local Area Networks (LAN)
      1. Wired LAN
         1. Common Media
            1. Ethernet cables
            2. Fiber optics
         2. Advantages
            1. High speed
            2. Reliability and stability
         3. Disadvantages
            1. Installation cost
            2. Limitation to fixed locations
      2. Wireless LAN (WLAN)
         1. Technologies
            1. Wi-Fi
            2. Infrared
         2. Advantages
            1. Mobility and ease of access
            2. Flexibility
         3. Disadvantages
            1. Security concerns
            2. Potential interference
      3. LAN Protocols
         1. Ethernet
         2. Wi-Fi (IEEE 802.11)
   3. Metropolitan Area Networks (MAN)
      1. Characteristics
         1. Spans a city or campus
         2. Intermediate range coverage
      2. Technologies
         1. Fiber optics
         2. Cable modem
      3. Usage and Applications
         1. Connecting multiple buildings within a city
         2. Public safety communications
   4. Wide Area Networks (WAN)
      1. Characteristics
         1. Large geographic area
         2. Generally slower than LANs
      2. Examples
         1. The Internet
         2. Corporate networks
      3. Technologies
         1. Leased lines
         2. MPLS (Multiprotocol Label Switching)
         3. Satellite links
      4. Advantages
         1. Connectivity across large distances
         2. Resource sharing
      5. Disadvantages
         1. Higher latency
         2. Complex infrastructure
   5. Enterprise Private Networks
      1. Characteristics
         1. Typically large, company-owned networks
         2. Tailored to business needs
      2. Components
         1. Intranets
         2. Extranets
      3. Advantages
         1. Security control
         2. Tailored for specific corporate communication needs
   6. Virtual Private Networks (VPN)
      1. Types
         1. Remote Access VPN
         2. Site-to-Site VPN
      2. Protocols
         1. PPTP (Point-to-Point Tunneling Protocol)
         2. L2TP (Layer 2 Tunneling Protocol)
         3. OpenVPN
      3. Uses
         1. Secure remote connections
         2. Anonymity and privacy online
      4. Advantages
         1. Improves security
         2. Can mask geographic location
   7. Storage Area Networks (SAN)
      1. Characteristics
         1. Dedicated network for data storage
         2. Used in enterprise environments
      2. Technologies
         1. Fibre Channel
         2. iSCSI (Internet Small Computer Systems Interface)
         3. FCoE (Fibre Channel over Ethernet)
      3. Applications
         1. Database hosting
         2. Backup and disaster recovery
   8. Cloud Networks
      1. Characteristics
         1. Virtualized resources and services
         2. Accessible over the Internet
      2. Types
         1. Public Cloud
         2. Private Cloud
         3. Hybrid Cloud
      3. Benefits
         1. Scalability
         2. Resource Optimization
      4. Key Challenges
         1. Security concerns
         2. Dependence on internet connectivity
   9. The Internet
      1. Architecture
         1. Global network of networks
         2. Uses TCP/IP protocols
      2. Key Features
         1. Ubiquitous access
         2. Supports a wide range of services
      3. Challenges
         1. Security threats
         2. Management complexity