Unit Test: testing phase in which individual units/modules of source code, associated with control data, usage procedures, and operating procedures, are tested to determine if they functionally satisfy their associated requirements. Successful completion of the individual unit tests creates a baseline to move to the next test phase.

Integration Testing - Integration testing is singular or multiple applications/systems/solutions that are combined and tested as a group with connections across prod-like environment(s) to validate the integrity of the complete system, exposing defects in the interfaces and in the interactions with the existing systems/applications/solutions

System Testing - System testing is conducted on the complete group of units/modules that make up an application/system/solution to evaluate compliance with its functional specified requirements

Performance Testing - Performance testing is testing performed to determine how a system performs in terms of responsiveness and stability under a particular workload (active vs concurrent users, etc.). It can also serve to investigate, measure, validate or verify other quality attributes of the system, such as scalability, reliability and resource usage

User Acceptance Testing – Formal testing conducted to determine whether or not a system satisfies its acceptance criteria and to enable the user to determine whether or not to accept the system as designed.Involves user/customer/business.

Test Plan: A document describing the scope, approach, resources, and schedule of intended test activities. It identifies test items, the features to be tested, the testing tasks, who will do each task, and any risks requiring contingency planning. IEEE Std 829-1983 5

Test Case: "A test case is a set of conditions or variables under which a tester will determine whether a system under test satisfies requirements or works correctly." It answers the question – What am I to test?

Test Execution Records: TER specify test environments (combination of platforms e.g. browsers, CPU, OS, Application Server, Databases etc.) that are used during testing as well as the high level results from a test case execution.

Test Script: contains the instructions for implementing a test case. It can either be manual/automated

Test Suite: A test suite is a collection of test cases grouped for execution purposes.

Defect: A defect is a deviation from the requirements, a flaw in a component or system that can cause the component or system to fail to perform its required function. Usually detected primarily during testing when it is determined that the actual result is different from the expected result.

Regression Testing: testing performed to ensure new changes or functionality to an application/system does not break the existing functionalities of the application/system