What is the Software Development Life Cycle (SDLC)?

SDLC is a structured process that describes all stages of software development, from idea inception to decommissioning.

Main stages:

• Planning: Defining software requirements, feasibility analysis, scheduling, and budgeting.
• Analysis: Gathering and documenting functional and non-functional requirements, creating specifications.
• Design: Developing system architecture, modules, databases, user interface.
• Development (Coding): Writing program code based on design documentation.

  # Example of simple code
  def hello_world():
      print("Hello, SDLC!")
  

• Testing: Verifying software functionality, identifying and fixing bugs. Includes unit, integration, system, and acceptance testing.
• Implementation (Deployment): Installing the finished software in the production environment, training users.
• Operation and Support: Monitoring software operation, troubleshooting, releasing updates and new versions.

SDLC models include:

Model	Description
Waterfall	Sequential execution of stages, no return.
Spiral	Iterative approach with risk management.
Iterative	Repeating development cycles with increasing functionality.
Agile	Incremental development, focus on adaptability.

The choice of model depends on the project specifics, customer requirements, and team. SDLC provides a systematic approach to development, improves software quality, and process predictability.