Internet and Other Technologies: formula sheet

Key formulas

Internet vs Web

Internet = infrastructure (TCP/IP network of networks); WWW = service on it (HTTP + URLs + browsers)

Web is a subset of what the Internet carries. Never use them as synonyms.

IPv4 size

32 bits; 2³² = 4,294,967,296 addresses

Written as four numbers 0-255 separated by dots.

IPv6 size

128 bits; 2¹²⁸ addresses

Written in hexadecimal groups separated by colons. Created to solve IPv4 exhaustion.

URL structure

protocol://domain-name/path

Example: https://www.example.in/notes. HTTPS means HTTP with encryption.

DNS function

Domain name → IP address

A resolver queries DNS servers, starting from the root, then TLD, then the authoritative server.

Governance roles

ICANN: names and identifiers; IANA: root zone, IP pools, protocol parameters; RIRs: regional IP allocation; IETF: protocol standards; W3C: Web standards

Learn one role per body for quick recall.

Service model split (who manages what)

IaaS: provider manages hardware and virtualisation; you manage OS, apps, data | PaaS: provider also manages OS and runtime; you manage apps and data | SaaS: provider manages everything; you manage use and data

The more control you hand over, the less customisation you keep. Data responsibility stays with you in all three.

Deployment models

Public = shared, provider-owned | Private = single organisation | Community = shared by organisations with common needs | Hybrid = two or more models combined

Hybrid lets sensitive data stay private while other workloads use public cloud.

Five essential characteristics

On-demand self-service + broad network access + resource pooling + rapid elasticity + measured service

Use as a definition checklist.

Examples to quote

IaaS: virtual servers and storage | PaaS: application development and database platforms | SaaS: email, CRM, accounting software

Generic examples are safe. Do not rely on brand names for marks.

Three-layer IoT architecture

Perception layer → Network layer → Application layer

Perception senses and acts; network transmits data; application delivers the service to the user.

Five-layer IoT architecture

Perception → Transport/Network → Processing (Middleware) → Application → Business

Use when the question asks for a detailed model. Say that layer names vary between sources.

IoT data flow

Sense → Connect → Process → Act/Inform

A simple answer to 'how does IoT work' that fits any example.

Security triad applied to IoT

Confidentiality, Integrity, Availability (CIA)

Use to structure risks: data leaks hit confidentiality, tampering hits integrity, DDoS or device failure hits availability.

Answer structure for IoT questions

Meaning → Architecture → Application → Risk → Legal/Compliance response

Keeps a descriptive answer complete and in a logical order.

Block structure

Block = transactions + timestamp + previous block hash + own hash

Linking each block to the previous hash is what makes tampering detectable.

Proof of Work vs Proof of Stake

PoW: right to add block = computing power spent; PoS: right to add block = coins staked

PoW is energy-heavy. PoS is energy-light but risks concentration among large holders.

Type by access

Public = permissionless; Private and consortium = permissioned

Use this to compare control, speed, privacy and trust.

Smart contract logic

IF condition met THEN action executes automatically

Legal validity depends on the essentials of a valid contract, not on the code alone.

Essentials of a valid contract

Offer + acceptance + lawful consideration + capacity + free consent + lawful object

Test a smart contract against these under the Indian Contract Act, 1872.

5 Vs of big data

Volume + Velocity + Variety + Veracity + Value

Learn each V with a one-line meaning and an Indian example.

AR vs VR

AR = real world + digital overlay; VR = fully virtual environment

VR replaces your surroundings. AR keeps them visible.

Edge vs cloud

Edge = process near the source; Cloud = process in remote central data centres

Edge gives low delay. Cloud gives large scale and storage.

Types of machine learning

Supervised, Unsupervised, Reinforcement

Supervised uses labelled data. Unsupervised does not. Reinforcement uses rewards.

E-commerce model by parties

B2B = business → business; B2C = business → consumer; C2C = consumer → consumer; C2B = consumer → business; B2G = business → government

Identify the two parties in the facts first. The seller side is named first in the usual B2C and B2B labels.

UPI payment flow

Payer app → payer's bank (UPI PIN authorisation) → NPCI UPI switch → payee's bank → credit to payee

Payment is account to account and real time. A wallet instead debits a stored balance held by the issuer.

Safe harbour condition

Intermediary protection = no initiation, selection or modification of the transmission + due diligence + takedown on lawful notice

Safe harbour is lost if the intermediary conspires, abets or fails to remove content after actual knowledge through a lawful order.

Significant social media intermediary extra duties

Chief Compliance Officer + nodal contact person + resident grievance officer + monthly compliance report

These apply only to intermediaries that cross the notified user threshold. Do not apply them to every platform.

Quick revision

• The internet is a global network of networks; the WWW is a service that runs on it, not the same thing.
• Know the main bodies and principles of internet governance as given in your study material.
• Cloud service models are IaaS, PaaS and SaaS; know one example and the user's control in each.
• Cloud deployment models are public, private, hybrid and community.
• IoT means connected devices that collect and exchange data, so device security and privacy are the main risks.
• Blockchain is a distributed ledger where records are linked in blocks and are hard to alter.
• Know the difference between public, private and consortium blockchains.
• Big data is usually described by volume, velocity and variety.
• Machine learning lets systems learn patterns from data instead of being told every rule.
• E-commerce models include B2B, B2C and C2C; know the legal issues around electronic contracts.
• Digital payments raise security, authentication and consumer protection issues.
• Social media raises issues of content liability, privacy and misuse; link them to the relevant law you study later.

Common mistakes

• Treating the Internet and the World Wide Web as the same thing. Fix: Say the Web is one service on the Internet. Mention email and FTP as non-Web uses.
• Saying ICANN owns or controls the Internet. Fix: Say ICANN coordinates names and identifiers. The Internet has no single owner and is governed through multiple bodies.
• Mixing up IaaS, PaaS and SaaS or giving only definitions. Fix: Always explain the split of responsibility and add one example for each.
• Saying the cloud provider alone is responsible for data security. Fix: State that the customer, as data owner, stays accountable and must secure the arrangement by contract and controls. Security is shared.
• Listing layers without explaining what each does Fix: Add one line and one example for every layer, such as a temperature sensor in the perception layer.
• Mixing three-layer and five-layer models in one answer Fix: Choose one model at the start and say that other sources may name the layers differently.
• Treating blockchain and Bitcoin as the same thing. Fix: State that blockchain is the technology and cryptocurrency is one application. Add other uses such as land records, supply chains and share registers.
• Saying blockchain data can never be changed. Fix: Say records are tamper-evident and very hard to alter. A group controlling most of the network, or a permissioned network's agreed rules, can change outcomes.
• Listing the 5 Vs by name without explaining them. Fix: Add a short meaning and an example to each V. Marks go to explanation.
• Saying AR and VR are the same, or mixing them up. Fix: Remember that VR replaces the real world, while AR overlays digital content on it.

Exam tips

• Expect a distinction or short note. Prepare a clean Internet versus Web contrast with three points.
• Learn one-line roles for ICANN, IANA, RIRs, IETF, W3C and NIXI. Examiners test who does what.
• Use a small example, such as a .in domain resolving to an IP address, to show you understand DNS rather than having memorised it.
• In case-based questions, finish with a practical compliance or security recommendation.
• Link to related topics such as IP addressing, network protocols and cyber law when the facts involve misuse of a domain or website.
• Answer comparison questions with a short table-like list in sentences: meaning, control, example, suitability. Do not write only definitions.
• In case questions, state the model first, then the legal issue, then the clause or action. This follows provision, analysis, conclusion.
• Never name a section or rule unless you are sure. Use plain words such as reasonable security practices and sector-specific directions.