Lesson Notes By Weeks and Term v5 - Grade 12
Networks, the internet and emerging technologies – Week 9 focus
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Networks, the internet and emerging technologies – Week 9 focus
Download the Lessonotes Mobile South Africa app for faster lesson access on Android and iPhone.
Subject: Information Technology
Class: Grade 12
Term: 2nd Term
Week: 9
Theme: General lesson support
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This week, we delve into the fascinating world of networks, the internet, and emerging technologies. Understanding how these systems work is crucial in today's interconnected world, particularly in South Africa. From online banking to accessing educational resources, from communicating with loved ones to participating in the global economy, these technologies underpin much of our daily lives. As future IT professionals, understanding these concepts will equip you to build, maintain, and innovate within these vital systems, contributing to a more digitally inclusive and advanced South Africa.
2.1 Network Topologies: A network topology refers to the arrangement of devices and connections in a network. Each topology has its own advantages and disadvantages in terms of cost, reliability, and ease of maintenance.
Bus Topology: In a bus topology, all devices are connected to a single cable (the bus). It's simple to set up, but a break in the cable can bring down the entire network. Imagine a small spaza shop connecting its computers and point-of-sale system using a single cable. If the cable is damaged, the entire shop's network is down.
Advantages: Low cost, easy to install.
Disadvantages: Single point of failure, difficult to troubleshoot, limited scalability.
Star Topology: In a star topology, all devices are connected to a central hub or switch. This is a common topology in modern networks. Think of a school computer lab. Each computer connects to a central switch. If one computer's connection fails, the rest of the network remains unaffected.
Advantages: Easy to troubleshoot, highly scalable, more reliable than bus.
Disadvantages: Requires more cable, central point of failure (hub/switch).
Ring Topology: In a ring topology, each device is connected to two other devices, forming a circular path. Data travels in one direction around the ring. Less common now.
Advantages: Simple to implement, data travels in one direction reducing collisions.
Disadvantages: A break in the ring disrupts the whole network, difficult to troubleshoot.
Mesh Topology: In a mesh topology, each device is connected to every other device (full mesh) or to a number of other devices (partial mesh). This provides high redundancy but is expensive to implement. Imagine a network of weather stations across South Africa, each directly connected to several others. If one station fails, data can still be routed through other stations.
Advantages: Highly reliable, fault tolerant.
Disadvantages: High cost, complex to implement.
Hybrid Topology: A hybrid topology combines two or more different topologies. A common example is a star-bus hybrid, where multiple star networks are connected via a bus backbone. This is frequently used in large organizations. 2.2 Client-Server vs.
Peer-to-Peer Networks: Client-Server: In a client-server network, one or more servers provide resources to clients. The server is a central point of control. Think of a school network where the server stores student files and manages printing. Clients (student computers) request services from the server.
Advantages: Centralized management, improved security, easier to back up data.
Disadvantages: More expensive to set up and maintain, server failure can disrupt the entire network.
Peer-to-Peer (P2P): In a peer-to-peer network, all devices are equal and can share resources directly with each other. No central server is required. Think of a small home network where family members share files and printers directly between their laptops.
Advantages: Lower cost, easy to set up.
Disadvantages: Less secure, difficult to manage, data backup is decentralized. 2.3 Cloud Computing: Cloud computing involves delivering computing services—including servers, storage, databases, networking, software, analytics, and intelligence—over the Internet (“the cloud”) to offer faster innovation, flexible resources, and economies of scale.
Infrastructure as a Service (IaaS): Provides access to fundamental computing infrastructure, such as virtual machines, storage, and networks.
Example: A South African startup uses AWS (Amazon Web Services) or Azure to host its web application infrastructure instead of buying and maintaining its own servers.
Advantages: Maximum flexibility, control over infrastructure.
Disadvantages: Requires significant technical expertise.
Platform as a Service (PaaS): Provides a platform for developing, running, and managing applications.
Example: A South African software development company uses Google App Engine or Heroku to develop and deploy its applications without worrying about the underlying infrastructure.
Advantages: Streamlined development process, reduced operational overhead.
Disadvantages: Limited control over infrastructure.
Software as a Service (SaaS): Provides access to software applications over the Internet.
Example: Many South African businesses use cloud-based accounting software like Xero or Sage One, or CRM solutions like Salesforce, paying a subscription fee to access the software.
Advantages: Easy to use, no installation or maintenance required.
Disadvantages: Limited customization options. 2.4 Emerging Technologies: IoT and AI: Internet of Things (IoT): Refers to the network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, and connectivity which enables these things to connect and exchange data.