Computer Science: Networking, Telecom, AI/ML, Big Data, Cloud/Edge Computing, IoT, Blockchain, Digital Currency, VR/AR, OTT, Social Media

Key Points at a Glance

1. 1

   Computer Networks

   • Interconnected computers sharing resources
   • Types by geography: PAN (~10m), LAN (building/campus), MAN (city), WAN (global — Internet is the largest WAN)
   • IP address: unique identifier for devices on network
   • IPv4: 32-bit; ~4.3 billion addresses — exhausted
   • IPv6: 128-bit; virtually unlimited
2. 2

   5G Technology

   • 5th Generation mobile network; theoretical peak speed 20 Gbps (vs. 4G's 1 Gbps)
   • Latency < 1 millisecond; supports 1 million devices per km²
   • Enables: autonomous vehicles, industrial IoT, smart cities, remote surgery
   • India's 5G rollout began October 2022 (Airtel and Jio in 13 cities)
   • 100+ cities covered by 2024
3. 3

   Artificial Intelligence (AI)

   • Simulation of human intelligence by machines
   • Machine Learning (ML): systems that learn from data
   • Deep Learning (DL): neural networks with many layers; basis of image recognition and NLP
   • NLP (Natural Language Processing): computers understanding/generating human language (ChatGPT, Alexa)
   • Computer Vision: image/video interpretation
4. 4

   Big Data

   • Defined by 5 Vs: Volume (terabytes to exabytes), Velocity (real-time streams), Variety (structured/unstructured text, images, video), Veracity (accuracy/trustworthiness), Value (business insights)
   • Hadoop: distributed storage framework
   • Apache Spark: real-time processing (100× faster than Hadoop MapReduce)
   • Also uses NoSQL databases
5. 5

   Cloud Computing

   • Delivers computing services over the Internet on a pay-per-use basis
   • IaaS (Infrastructure as a Service): AWS EC2, Azure VMs
   • PaaS (Platform as a Service): Google App Engine
   • SaaS (Software as a Service): Gmail, Office 365
   • Edge computing: processes data near its source (IoT devices, factories); reduces latency
6. 6

   Internet of Things (IoT)

   • Network of physical objects embedded with sensors, software, and connectivity to collect and exchange data
   • Examples: smart home devices (Alexa, smart thermostat), wearable fitness trackers, industrial sensors
   • Smart agriculture (soil moisture sensors), connected vehicles, smart city infrastructure
   • By 2025, ~75 billion IoT devices projected globally
7. 7

   Blockchain

   • Distributed Ledger Technology (DLT): chain of blocks containing transaction records, cryptographically linked
   • Replicated across a peer-to-peer network
   • Decentralised: no single authority; Immutable: records cannot be altered; Transparent: all participants can verify
   • Bitcoin (2009, Satoshi Nakamoto) was the first blockchain application
8. 8

   Digital Currency

   • Cryptocurrency: decentralised, blockchain-based (Bitcoin, Ethereum); no central authority
   • CBDC (Central Bank Digital Currency): government-issued digital legal tender
   • India's Digital Rupee (e₹) by RBI: Wholesale e₹ pilot (November 2022), Retail e₹ pilot (December 2022)
   • Unlike cryptocurrency, e₹ is centralised and backed by RBI
9. 9

   VR / AR / MR

   • VR (Virtual Reality): fully immersive computer-generated environment via headsets (Oculus, Meta Quest, Sony PlayStation VR)
   • AR (Augmented Reality): overlays digital information on real world (Pokémon Go, Google Glass, Apple Vision Pro)
   • MR (Mixed Reality): blends real and digital objects that interact
   • Applications: gaming, education, medical simulation, military training, tourism
10. 10

    OTT Platforms

    • Deliver media content directly over the Internet, bypassing traditional cable/satellite TV
    • India has 45+ OTT platforms; top global: Netflix (238 million subscribers), Amazon Prime, Disney+Hotstar, YouTube
    • Jio Cinema: IPL 2023 — record 32 million concurrent viewers
    • Regulated by MIB under IT Rules 2021
11. 11

    Social Media

    • Web-based platforms allowing creation, sharing, and exchange of user-generated content
    • Major platforms: Facebook (3.05 billion MAU), YouTube (2.5 billion), WhatsApp (2 billion), Instagram (2 billion), TikTok (1.5 billion), Twitter/X (250 million)
    • India has 500 million+ social media users (2024)
    • IT (Intermediary Guidelines and Digital Media Ethics Code) Rules 2021 governs social media intermediaries in India
12. 12

    Machine Learning Types

    • Supervised Learning: learns from labelled examples (spam detection, image classification, price prediction)
    • Unsupervised Learning: finds patterns in unlabelled data (customer segmentation, anomaly detection)
    • Reinforcement Learning: agent learns by trial and error with rewards/penalties (AlphaGo, robotics, self-driving cars)
13. 13

    Generative AI (GenAI)

    • AI systems that create new content: text, images, music, code, video
    • Key models: GPT-4 (OpenAI), Gemini (Google DeepMind), Claude (Anthropic), Llama (Meta)
    • Image generation: Stable Diffusion, DALL-E, Midjourney
    • ChatGPT reached 100 million users in 60 days (November 2022) — fastest-growing consumer app in history
14. 14

    Quantum Computing

    • Uses quantum bits (qubits) exploiting superposition and entanglement
    • Potential to break current RSA encryption (Shor's algorithm) → driving post-quantum cryptography
    • Applications: drug discovery, financial optimisation, climate modelling, AI acceleration
    • IBM Quantum Eagle (2021): 127 qubits; IBM Condor (2023): 1,121 qubits