What are the types of requirements? Can you list them according to some classification?

Requirements can be classified according to various criteria:

1. By level of detail:

   • Business requirements — describe the goals and objectives of the business.
   • User requirements — what the product should be able to do from the user's perspective.
   • System requirements — technical characteristics and constraints of the system.

2. By type:

   • Functional requirements — describe the functions and behavior of the system.
   • Non-functional requirements — requirements for performance, security, usability, etc.

3. By source:

   • External (customer requirements, legislation).
   • Internal (development team requirements, standards).

4. By priority:

   • Mandatory.
   • Desirable.
   • Additional.

5. By method of documentation:

   • Explicit (documented).
   • Implicit (assumed, informal).

This classification helps structure requirements and manage them during the development process.