What are the classifications of testing?

Testing classifications can be based on various criteria. The most common:

• By testing goal:

  • Functional testing
  • Non-functional testing
  • Change-related testing

• By testing object:

  • Unit
  • Integration
  • System
  • Acceptance

• By testing timing:

  • Alpha testing (within the company)
  • Beta testing (with limited external user group)
  • Regression testing
  • Sanity testing
  • Smoke testing

• By access level to the code:

  • White-box (Structural testing)
  • Black-box (Behavioral testing)
  • Gray-box testing

• By degree of formalization:

  • Formal testing (based on exhaustive specifications)
  • Informal testing (exploratory, ad-hoc)

• By automation level:

  • Manual testing
  • Automated testing

• By application type:

  • Web applications
  • Mobile applications
  • Desktop applications
  • API
  • Databases

• By other criteria:

  • Load testing
  • Stress testing
  • Stability/Reliability testing
  • Usability testing
  • Security testing
  • Cross-browser/cross-platform testing

Example of classification structure in tabular form:

Classification Criterion	Types of testing	Description
By goal	Functional	Verification of compliance with specification requirements
	Non-functional	Performance, security, usability, etc.
	Change-related	Regression, retesting
By object	Unit	Individual code units
	Integration	Interaction between modules or systems
	System	Whole system as a single entity
	Acceptance	Readiness check for product release
By code access level	Black-box	No access to source code, based on specifications
	White-box	With access to source code
	Gray-box	Partial access, knowledge of internal logic without full code traversal