Chapter 2 – Communication

2.1 Networking  

2.1.1 Networking Devices  

- Hub → connects devices, broadcasts to all.  

- Switch → directs packets using MAC addresses.  

- Router → connects networks (LAN → WAN).  

- Modem → converts digital ↔ analog signals.  

- Repeater → boosts signals over distance.  

- Access Point (AP) → connects wireless devices to wired networks.  

2.1.2 Networking Models  

- Client‑Server → central server manages resources; scalable, secure.  

- Peer‑to‑Peer → all nodes share resources; simple, less secure.  

2.1.3 Network Topologies  

- Bus → single cable, cheap, prone to collisions.  

- Star → central hub; hub failure = network failure.  

- Mesh → interconnected, redundant, complex setup.  

- Hybrid → mix of topologies for flexibility.  

2.1.4 Cloud Computing  

- Public Cloud → shared, internet‑based.  

- Private Cloud → dedicated, secure.  

- Hybrid Cloud → mix of both, flexible.  

2.1.5 Wired vs Wireless  

- Wired → reliable, faster, less mobile.  

- Wireless → mobile, but interference and slower speeds are possible.  

2.1.6 Hardware Requirements  

- Hub/Switch → connects LAN devices.  

- Router → connects LANs into WAN.  

- NIC → device network connection.  

- Access Points → wireless connectivity.  

2.1.7 Ethernet  

- IEEE 802.3 standard.  

- Uses CSMA/CD (carrier sense multiple access with collision detection).  

2.1.8 Bit Streaming  

- Continuous transmission of bits.  

- Real‑time → live broadcasts.  

- On‑demand → video streaming.  

2.2 The Internet  

2.2.1 Internet vs WWW  

- Internet → global network of computers.  

- World Wide Web → information accessed via the Internet using browsers.  

2.2.2 Hardware & Software  

- Hardware → routers, modems, servers, infrastructure.  

- Software → browsers, email clients, communication tools.  

2.2.3 IP Addresses  

- Unique device identifiers.  

- IPv4 → limited space.  

- IPv6 → larger address space.  

2.2.4 URLs  

- Specifies resource address: protocol + domain + path.  

2.2.5 DNS  

- Translates domain names → IP addresses.  

- Enables human‑readable website access.  

2.2.6 Scripting in HTML  

- Client‑side scripting (e.g., JavaScript).  

- Enables dynamic, interactive web pages.  

Summary:  

Chapter 2 covers networking devices, models, topologies, and cloud computing, alongside internet fundamentals like IP addresses, DNS, and HTML scripting. It emphasizes how networks connect, how data flows, and how the internet infrastructure supports communication globally.