Testing can never completely identify all the defects within software.[2] Instead, it furnishes a criticism or comparison that compares the state and behavior of the product against oracles-principles or mechanisms by which someone might recognize a problem. These oracles may include (but are not limited to) specifications, contracts,[3] comparable products, past versions of the same product, inferences about intended or expected purpose, user or customer expectations, relevant standards, applicable laws, or other criteria. A primary purpose of testing is to detect software failures so that defects may be discovered and corrected. Testing cannot establish that a product functions properly under all conditions but can only establish that it does not function properly under specific conditions.[4] The scope of software testing often includes examination of code as well as execution of that code in various environments and conditions as well as examining the aspects of code: does it do what it is supposed to do and do what it needs to do. In the current culture of software development, a testing organization may be separate from the development team. There are various roles for testing team members. Information derived from software testing may be used to correct the process by which software is developed.[5] Every software product has a target audience. For example, the audience for video game software is completely different from banking software. Therefore, when an organization develops or otherwise invests in a software product, it can assess whether the software product will be acceptable to its end users, its target audience, its purchasers, and other stakeholders.

The Reason & Importance of Testing

It is very important to have decent quality software's. Having this means the quality should match many requirements such as keeping the easy use of GUI's, as well as containing faults and failures and many more. A lot of effort is required to keep this quality to a reasonable standard. Testing is one of the most important parts in quality assurance especially in the development stages. As the development of the program comes to an end it becomes harder to fix errors, in fact becomes harder to spot errors. This would mean, perhaps, to check each section during the development so that the errors can be spotted and fixed before progressing to the next stages.
Testing should be done during the development stages and if it is not done during the development stages then it is more than likely that there will be a lot of bugs and errors. Some problems which may not have been seen during the development stages, without testing at the end, could be something like a function being used whilst the stack is empty. This could lead to a system crashing. However, if testing is done this could be spotted before proceeding to the next stage.
Humans are prone to make mistakes and so if they do everything then it may not be as efficient. Some code may be missed out with humans and so this could cause errors in the system.

Testing tools can help automate tasks such as product installation, test data creation, GUI interaction, problem detection (consider parsing or polling agents equipped with oracles), defect logging, etc., without necessarily automating tests in an end-to-end fashion. One must keep satisfying popular requirements when thinking of test automation:
Platform and OS independence
Data driven capability (Input Data, Output Data, Metadata)
Customizable Reporting (DB Access, crystal reports)
Easy debugging and logging
Version control friendly - minimal binary files
Extensible & Customizable (Open APIs to be able to integrate with other tools)
Common Driver (For example, in the Java development ecosystem, that means Ant or Maven and the popular IDEs). This enables tests to integrate with the developers' workflows.
Support unattended test runs for integration with build processes and batch runs. Continuous integration servers require this.
Email Notifications (automated notification on failure or threshold levels). This may be the test runner or tooling[clarification needed] that executes it.
Support distributed execution environment (distributed test bed)
Distributed application support (distributed SUT)
As the software industry grows, it becomes more and more competitive and advanced for businesses to produce such good quality software. With this also comes the reliability and deadlines which must be met. Testing plays a big part in the case of deadlines as testing can take a long time on the software. The production of the software and the quality together must be increased for businesses to produce the best possible software. Testing, therefore, has to be done throughout the process of programming the software. Manual testing takes too long and can waste a lot of time. With the aid of testing tools this can increase efficiency and get the deadlines met.

What are testing tools ?

Testing tools are a form of automated testing. It is basically using programs to do different testing tasks i.e. doing the tests through some form of automated method. They are computerized and help in assisting every type of testing. Some of these testing tasks include checking the conditions, also checking the predicted results with the actual results along with many other types of testing involved. A lot of these testing tools have commonly used coding languages such as Java and C. The testing tools themselves have been made using these programming languages. A lot of the tools used have different options available to help with testing. This can be very useful when producing the essential reports of that particular product.

Different Methodologies Used For Testing

There are different methodologies that are can be used when implementing testing tools. The testing methodologies can be used together or individually. It all depends on what you are testing as they provide better resources for different tasks. Below are a few of the main different types that are used but there are other types of testing that can be used:

Unit Testing

This is the software used for verification and validation. It's a method in which the programmer can test all the separate code and see if it is viable to use. This type of testing is based on a small scale and uses small units of the program. When looking at procedural programming the unit can be any individual function or a procedure which is written in the same language as the production code.

White Box Testing

This is also known as clear box testing, glass box testing, translucent box testing or structural testing. It uses the internal perspective of the system and then designs test cases based on this internal structure. Basically the code itself and all the conditions, statements and paths along with it are tested. Programming skills are required for noticing all the paths through the software. White box testing does many things such as analyzing the data flow, control flow, information flow and coding practices.

Regression Testing

This is a type of software testing which basically looks for software regressions. The regressions can happen whenever the software stops working as it is meant to. The testing makes sure that any bugs or changes have been fixed which may have caused previous working functions to have failed as a result of the newly added features. It is better to do this type of testing under the automated tool environment. The regression testing may take place once the programmer has tried to fix a problem or has purposely added in code to give out errors.

Integration Testing

This is where the separate software modules are put together and are then tested as a whole. This normally takes place after unit testing has been done. The point of doing integration testing is because it verifies the functional and performance requirements of the design items. It is component of Extreme Programming (XP). Two different ways of doing integration testing is bottom-up and top-down.