Tell me about the Waterfall software development model.

Waterfall Model — this is a linear sequential approach to software development, where each stage is completed before the next begins.

Stages:

1. Requirements: Gathering and analyzing all system requirements.
2. Design: Developing the architecture and design of the system.
3. Implementation: Writing the code.
4. Testing: Detecting and fixing defects.
5. Deployment and maintenance: Implementing the system and its servicing.

Advantages:

• Simple and understandable structure.
• Clear definition of stages and roles.
• Easy to manage projects with fixed requirements.

Disadvantages:

• Low flexibility to changes in requirements at later stages.
• Testing begins only after the development is completed.
• High risk if initial requirements are incorrectly gathered.

Application:

Suitable for projects with:

• Well-defined and stable requirements.
• High demands on security and reliability (e.g., aviation, medical equipment).
• Low likelihood of changes during development.