1. Waterfall Methodology

A linear and sequential project management approach. Each phase (e.g., requirements, design, implementation) must be completed before moving to the next.
Key Features:
- Fixed project scope and timeline.
- Requirements are well-documented upfront.
- Suitable for predictable and less flexible projects.
- No scope for changes during development.
Advantages:
- Easy to understand and manage.
- Works well for small, well-defined projects.
Disadvantages:
- Inflexible; hard to adapt to changes.
- Late discovery of issues.

2. Agile Methodology

An iterative and incremental project management approach focused on flexibility and continuous feedback.
Key Features:
- Projects are divided into small, manageable chunks called iterations or sprints.
- Continuous collaboration with stakeholders.
- Focus on working software over documentation.
- Allows changes even late in development.
Advantages:
- High adaptability to changes.
- Faster delivery of features.
- Better customer satisfaction.
Disadvantages:
- Requires experienced team members.
- Scope creep is common if not managed properly.

A framework within Agile for managing and completing projects in short iterations (sprints).
Key Components:
- Roles:
  - Product Owner: Defines the product vision and prioritizes work.
  - Scrum Master: Ensures the Scrum process is followed and removes obstacles.
  - Development Team: Builds the product.
- Artifacts:
  - Product Backlog: List of all features/tasks.
  - Sprint Backlog: Tasks selected for a sprint.
  - Increment: Completed deliverables at the end of a sprint.
- Events:
  - Sprint Planning: Defines goals for the sprint.
  - Daily Standup: Short daily meeting to track progress.
  - Sprint Review: Showcasing completed work to stakeholders.
  - Sprint Retrospective: Reflecting on what went well and what can improve.
Advantages:
- High team collaboration.
- Quick delivery of prioritized features.
Disadvantages:
- Can be challenging for large teams or long-term projects.
- Requires constant commitment from all members.

Aspect	Waterfall	Agile	Scrum
Approach	Linear, sequential	Iterative, flexible	Iterative, team-focused
Flexibility	Low	High	High
Documentation	High	Minimal	Minimal
Team Size	Large or small	Small to medium	Small, self-organizing teams
Customer Involvement	Low	High	Very high

Waterfall:
- Clear requirements and fixed deadlines.
- Projects with minimal changes (e.g., construction).
Agile:
- Dynamic and evolving requirements.
- Technology/software projects.
Scrum:
- Small teams working on software projects with tight collaboration.