What Is The Difference Between Test Plan And Test Strategy?

Test Plan is a document which describes the scope, approach and schedule of testing activities or you can also say that it contains "what we will test in software", "how we will test it", "when we test it as timing of testing" and "who will perform testing". It is the responsibility of test lead to develop this document.

Usually a test plan contains following things.
(1) Scope of testing
(2) Testing approach
(3) Time frame
(4) Objectives of testing
(5) What will be the environment
(6) What will be the deliverables
(7) Risk factors
(8) Features to be tested

Test strategy is also a document and it is the responsibility of the project manager to develop it. It contains which techniques we will use and what will be the module to test. Here technique means type of testing. As different testing techniques can be applied to test software based on our goals. For example stress and load testing is applied on web based applications. We have to decide which testing approach we will use to test a module as following testing approaches can be used.

(1)Black Box Testing (2) White Box Testing (3) Ad-hoc testing (4) Acceptance Testing (5) Recovery testing (6) Sanity testing (7) Smoke testing (8) Regression testing (9) End to End Testing (10) System Testing (11) Functional Testing (12) Unit Testing (13) Alpha Testing
(14) Beta Testing (15) Exploratory Testing etc.

Test plan is a document which provides complete details about the resources which are used in a project. Also describe the scope, approach and other activities which we perform during testing. It is the responsibility of test lead to develop this document. It contains what things we are going to test, how we test it, when we test it and who will test it. I would like to mention key elements of a test plan which we mention when we create a test plan, which are given below.

(1) Test scope and its objectives: Here we mention the objectives of testing a particular module.
(2) Testing Strategy: Here we describe the strategy we used for testing the software.
(3) Deliverables of the test case: What we will get after executing testing.
(4) Test cases: We mention test cases for different modules.
(5) Test Requirements: Here we mention the necessary requirements for tests.
(6) Expected Result: it means that what result we expect after performing testing.
(7) Testing Environment: It means that what will be the software and hardware requirements for testing the software.

Test Strategy: It is the job of project manager to develop this document. This document contains which type of testing technique we will use for testing the software. As there are many types of software testing which are used in different circumstances for different purposes and it depends on the situation to choose a particular strategy.

A test strategy is basically a higher level document that documents the approach used for testing. It outlines the scope of product, issues, deliverable of the test, tools to be used, risk analysis etc. On the other hand a test plan is a document that outlines the essentials of the actual test. How will the test strategy be implemented, where, when and how.

Test plan is defined as a methodical approach to test any product (could be a software product or a machine)
An overview of what is contained in the test plan is given below for further details please visit the following website (en.wikipedia.org
Sample test plan includes
Introduction – includes the overview of the system, purpose of the document and objective of the system test
Scope and objective- defines the testing scope and testing process
Test phases and cycle
The resources allocated for testing which would include hardware, software and human resources.
Management plan- defines the role and responsibilities of the management team, the testing team and the external support team (if required)
Finally the risks and error analysis
Test strategy is a plan which defines how to carry out the testing procedure for further details regarding test strategy templates please visit the following website (www.projectperfect.com.au/info_test_strategy.php)
Test strategy includes:
Overview-includes the type of test to be carried out, its time, location and     resources allocated to it
Testing Environment- includes the software requirements, equipments required, the data used
Procedures – should include Problem Identification, defect rectification, retesting, sign-off testing activities
Release Management- defines the release management consideration
Define the software tools used for testing

Hey you have not answered for the question.. If you know tell that what is the difference between both. Not to describe about both..

Practically both of them are same! Theoretically they differ in some aspects; coz a project may run with out test strategy but not with test plan. Test Strategy is the subset of test plan.