The Levels of Testing:- 1. Unit Testing Testing individual small parts (functions or modules) Done by developers Example: Test only login function 2. Integration Testing Testing combined modules together Checks data flow between modules Example: Login module + Database connection Basic Approaches of Integration Testing 1.Top-Down Approach Testing starts from top module to lower modules Uses stubs for lower modules Main functionality tested early 2. Bottom-Up Approach Testing starts from lower modules to top modules Uses drivers to test lower modules Core logic tested first 3. Big Bang Approach All modules integrated at once No stubs or drivers used Difficult to find exact bug location 4. Critical Path Approach Test most important user flow first Focus on business-critical features Reduces major business risk Simple Comparison Approach Starts From Uses ...