Comprehensive SDLC and Computer Organization Key Concepts for Students

What does SDLC stand for

Software Development Life Cycle.

Purpose of SDLC

To build software step by step, reduce errors, and save time and cost.

Definition of SDLC

A structured process to design, develop, test, and deliver software.

Importance of learning SDLC

Helps manage complex projects, reduces cost and errors, and is a high-demand career skill.

Planning phase of SDLC

Identify needs, set goals, and perform a feasibility study.

Key skills for Planning phase

Communication and business analysis.

Requirement Analysis phase

Gather requirements from clients/users.

Key skills for Requirement Analysis phase

Documentation, interviewing, and data gathering.

Design phase of SDLC

System architecture, UI/UX design, diagrams, and prototypes.

Key skills for Design phase

UML diagrams, wireframes, prototyping.

Development phase of SDLC

Programmers write the actual code.

Skills needed for Development phase

Python, Java, C++, frameworks.

Testing phase of SDLC

Find and fix bugs before release.

Skills needed for Testing phase

QA, automation tools.

Deployment phase of SDLC

Software goes live (App Store, website, etc.).

What are the skills needed for Deployment phase

Cloud (AWS, Azure, GCP), DevOps.

Maintenance phase of SDLC

Updates, bug fixes, and security patches.

Skills needed for Maintenance phase

Monitoring, debugging, customer support.

Real-World Example (TikTok)

For every update → Planning → Requirements → Design → Coding → Testing → Deployment → Maintenance.

Common SDLC models

Waterfall, Agile, Spiral, V-Model.

Most popular SDLC model today

Agile.

Difference between Waterfall and Agile

Waterfall is step-by-step and rigid; Agile is iterative and flexible.

Careers related to SDLC

Business Analyst, UI/UX Designer, Developer, Test Engineer, DevOps Engineer, Project Manager, Scrum Master.

High demand SDLC-related roles

Software developers, analysts, and DevOps engineers.

First phase of SDLC

Planning.

Who ensures software is bug-free?

Test Engineer / QA.

Which SDLC phase uses cloud platforms?

Deployment.

Main purpose of SDLC

To create reliable software step by step.

What does each SDLC phase provide?

Its own career opportunities.

Computer organization

The bridge between hardware and software; deals with the operational structure and behavior of a computer.

Focus of computer organization

How components work and interact.

Major components of computer organization

Input Unit, Output Unit, CPU (CU, ALU, Registers), and Memory Unit (Primary & Secondary Storage).

3 sub-units of the CPU

Control Unit (CU), Arithmetic Logic Unit (ALU), and Registers.

What does the Control Unit (CU) do?

Directs operations of the computer.

What does the Arithmetic Logic Unit (ALU) do?

Performs calculations and logical operations.

What are registers?

Small, very fast storage locations inside the CPU.

Memory hierarchy (from fastest to slowest)

Registers → Cache → Main Memory (RAM) → Secondary Storage → Tertiary Storage.

Importance of memory hierarchy

Balances speed, cost, and capacity.

Overall explanation of computer organization

How hardware components (CPU, memory, I/O devices) interact and execute programs.

Process of the Waterfall Model

Step-by-step (linear; once a phase is done, you can't go back).

How does the Waterfall Model handle changes?

Hard to change requirements after the project starts.

When is the final product delivered in the Waterfall Model?

At the end of the project.

User involvement in the Waterfall Model

Low (mostly at the start and end).

Projects best suited for the Waterfall Model

Projects with clear requirements (e.g., banking, government systems).

Process of the Agile Model

Iterative & flexible (work done in small cycles called sprints).

How does the Agile Model handle changes?

Easy to adapt to new changes anytime.

When is software delivered in the Agile Model?

In small working parts during the project.

User involvement in the Agile Model

High (users give feedback every sprint).

Projects best suited for the Agile Model

Projects with evolving requirements (e.g., apps, startups, web platforms).