Sri Lanka ICT Service Exam cheat sheet
Sri Lanka ICT Service Exam · Keep the key ideas within reach.
ICT Fundamentals
Data is raw facts; information is processed data with meaning; knowledge is applied information.
Bit = binary digit (0 or 1); 1 byte = 8 bits; 1 KB = 1024 bytes (binary) or 1000 bytes (decimal).
Von Neumann architecture: CPU, memory, I/O, and stored-program concept with shared bus.
CPU fetch-decode-execute cycle: fetch instruction from memory, decode opcode, execute, store result.
Primary memory (RAM/ROM) is directly accessible by CPU; secondary storage (HDD/SSD) is non-volatile.
Number systems: binary base-2, octal base-8, decimal base-10, hexadecimal base-16; convert by grouping bits.
ASCII uses 7 bits (128 characters); Unicode (UTF-8/16) supports multilingual text.
Cloud service models: IaaS (infrastructure), PaaS (platform), SaaS (software); deployment: public, private, hybrid.
Computer Hardware
Motherboard connects CPU, RAM, storage, and peripherals via buses (PCIe, SATA, USB).
CPU performance factors: clock speed (GHz), cores, cache size (L1/L2/L3), and instruction set.
RAM is volatile working memory; ROM is non-volatile firmware storage (BIOS/UEFI).
HDD uses magnetic platters; SSD uses NAND flash; SSD has faster access, no moving parts.
Power supply unit (PSU) converts AC to DC; wattage must exceed total component draw.
Input devices: keyboard, mouse, scanner, sensor; output devices: monitor, printer, speaker.
Ports: USB (universal), HDMI (video/audio), Ethernet RJ-45 (network), VGA (analog video).
RAID 0 stripes for performance (no redundancy); RAID 1 mirrors; RAID 5 stripes with parity (fault tolerance).
Operating Systems and Networking
OS functions: process management, memory management, file system, device I/O, and user interface.
Process states: new, ready, running, waiting, terminated; scheduler moves processes among states.
Virtual memory uses paging/segmentation to extend RAM using disk space; thrashing occurs under excessive paging.
OSI 7 layers: Physical, Data Link, Network, Transport, Session, Presentation, Application.
TCP/IP model: Network Access, Internet, Transport, Application; TCP is connection-oriented, UDP is connectionless.
IPv4 address is 32-bit; IPv6 is 128-bit; private ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16.
DNS resolves domain names to IP addresses; DHCP assigns IP configuration automatically.
Common ports: HTTP 80, HTTPS 443, FTP 21, SSH 22, SMTP 25, DNS 53.
Database Management and Information Systems
DBMS provides controlled access, integrity, backup/recovery, and concurrent access to data.
Relational model: tables (relations), rows (tuples), columns (attributes), primary key uniquely identifies rows.
Foreign key enforces referential integrity between related tables.
Normalization: 1NF atomic values; 2NF no partial dependency; 3NF no transitive dependency.
SQL categories: DDL (CREATE/ALTER/DROP), DML (SELECT/INSERT/UPDATE/DELETE), DCL (GRANT/REVOKE), TCL (COMMIT/ROLLBACK).
ACID properties: Atomicity, Consistency, Isolation, Durability for reliable transactions.
ER diagram: entities, attributes, relationships (1:1, 1:N, M:N); cardinality shows participation.
Information system types: TPS (transaction), MIS (management reporting), DSS (decision support), EIS (executive).
Software Engineering and Systems Development
SDLC phases: requirements, design, implementation, testing, deployment, maintenance.
Waterfall is sequential; Agile is iterative with sprints and continuous feedback.
Requirements types: functional (what system does) and non-functional (performance, security, usability).
UML diagrams: use case (actors and functions), class (structure), sequence (interaction over time).
Testing levels: unit, integration, system, acceptance; black-box vs white-box techniques.
Version control (Git) tracks changes; branching and merging support parallel development.
Software quality attributes: reliability, maintainability, scalability, portability, usability.
DevOps integrates development and operations through CI/CD pipelines and automation.
Information Security and Data Protection
CIA triad: Confidentiality (secrecy), Integrity (accuracy), Availability (access when needed).
Authentication verifies identity; authorization grants permissions; accounting/audit logs actions.
Encryption: symmetric (same key, e.g., AES) vs asymmetric (public/private key, e.g., RSA).
Hashing (SHA-256) provides integrity checks; digital signature combines hashing and asymmetric encryption.
Common threats: malware, phishing, DoS/DDoS, SQL injection, man-in-the-middle, insider threat.
Security controls: preventive, detective, corrective; categories: technical, administrative, physical.
Data protection principles: lawful purpose, minimal collection, accuracy, retention limits, security safeguards.
Incident response phases: preparation, identification, containment, eradication, recovery, lessons learned.
Digital Government and e-Services
e-Government models: G2C (citizen), G2B (business), G2G (government), G2E (employee).
Digital government stages: information publishing, interaction, transaction, integration, transformation.
Interoperability enables data exchange across agencies via standards and APIs.
Digital identity (e-NIC, digital certificate) supports secure online service access.
e-Service quality dimensions: accessibility, responsiveness, reliability, transparency, security.
Single window / one-stop shop consolidates multiple services into a unified portal.
Open data publishes government datasets for reuse, transparency, and innovation.
Digital inclusion addresses access barriers: connectivity, affordability, skills, language, disability.
ICT Project Management and Procurement
Project constraints: scope, time, cost, quality; changes affect the triple constraint.
PMBOK process groups: initiating, planning, executing, monitoring/controlling, closing.
Work Breakdown Structure (WBS) decomposes deliverables into manageable work packages.
Critical Path Method (CPM) identifies longest dependent path; float/slack is delay tolerance.
Risk management: identify, analyze (qualitative/quantitative), plan response, monitor.
Procurement methods: open tender, restricted tender, direct contracting, request for proposal (RFP).
Bid evaluation criteria: technical compliance, price, past performance, support capability.
Contract types: fixed-price (seller bears cost risk), time-and-materials, cost-reimbursable.
ICT Policy, Law and Professional Ethics
Intellectual property: copyright (expression), patent (invention), trademark (brand), trade secret.
Software licensing: proprietary, open source (GPL, MIT, Apache), freeware, shareware.
Cybercrime laws criminalize unauthorized access, data interference, fraud, and content offenses.
Data protection law requires lawful basis, consent, purpose limitation, and data subject rights.
Professional ethics: competence, integrity, confidentiality, objectivity, accountability.
Computer misuse includes hacking, malware distribution, identity theft, and unauthorized interception.
Electronic transactions law recognizes e-signatures and electronic records in legal proceedings.
Whistleblowing and conflict-of-interest disclosure support ethical governance.
Emerging Technologies and Digital Transformation
Cloud computing characteristics: on-demand self-service, broad access, resource pooling, elasticity, measured service.
Big Data 5 Vs: Volume, Velocity, Variety, Veracity, Value.
IoT connects sensors and devices to networks for monitoring and automation.
AI/ML: supervised (labeled data), unsupervised (clustering), reinforcement (reward-based) learning.
Blockchain is a distributed immutable ledger using cryptographic hashing and consensus.
5G features: high bandwidth, low latency, massive device connectivity.
RPA automates repetitive rule-based tasks; low-code platforms speed application delivery.
Digital transformation integrates technology, processes, and culture to redesign service delivery.
Public Administration
Public administration implements government policy and delivers public services.
Good governance principles: accountability, transparency, rule of law, participation, equity, efficiency.
Bureaucracy (Weber) features hierarchy, rules, division of labor, merit-based appointment.
New Public Management emphasizes results, citizen orientation, and market-based mechanisms.
Public financial management covers budgeting, accounting, auditing, and procurement.
Administrative law governs decisions, fairness, natural justice, and judicial review.
Civil service values: impartiality, integrity, service orientation, confidentiality.
e-Government supports administrative reform through digitization and process reengineering.
General Knowledge and Current Affairs
Sri Lanka is an island nation in South Asia; capital Sri Jayawardenepura Kotte; commercial capital Colombo.
Sri Lanka's official languages: Sinhala and Tamil; link language English.
United Nations Sustainable Development Goals (SDGs) comprise 17 goals adopted in 2015.
Sri Lanka ICT initiatives include the National ICT Policy, ICTA, and digital government programs.
World organizations: UN, WHO, IMF, World Bank, WTO, ITU, UNESCO.
ITU is the UN agency for information and communication technologies.
Current affairs: monitor official government gazettes and reputable news for policy updates.
Digital economy indicators: internet penetration, broadband adoption, e-payment usage.