What is the difference between automated testing and manual testing?

Automated scripted testing and manual scripted are two most common and popular ways of carrying out the scripted testing. Scripted testing is performed by a set of test scripts which can be defined as a set of instructions that are to be performed on the software system or application under the test to test a particular functionality as required.

Automated testing is mostly used.
- In automated testing the test cases are executed automatically and there is no need of human intervention.

- Non- requirement of human intervention is the best advantage of automated testing.

- It can be easily repeated and is faster than manual testing.

- It is very useful when it is required to run the same tests over and over again.

- It is performed as a part of regression testing.

- The main drawback of automated testing is that the automated tests are poorly written and they may break down or crash during the execution.

- They only test what has been programmed into them.

- They only ensure that old bugs do not reappear and don’t prove to be a good methodology to find out new bugs and errors.

In contrast to automated testing the manual scripted testing is the oldest and most rigorous form of software and application testing.
- In manual testing the test cases are reviewed by the whole testing team before putting them in to execution.

- These test cases are created at two levels.

- The first level is basic functionality level and the second one is the scenario level.

- Apart from reviewing of test cases, the designing is also done by the whole software development team.

- Manual scripted testing is considered to be a waste of resources by most of the testers.

- According to some testers the scripted manual testing inhibits the mind of the tester to use their creativity and also this testing requires heavy documentation as well as considerable amount of resources to create them.

- They often get out dated since the changes in the system are inevitable.

- Though being so criticized manual scripted testing is used by many organizations.

- The test cases are made repeatable and easy enough for a tester to perform testing with minimum supervision.

- Manual scripted testing is used in contracts where contractual agreement states that written requirements and specifications of the software must be met.

- Scripted test cases are useful where the tests are used for the benchmarking purpose and have to be executed in the same way, every time.

- The testers should have a strong knowledge of the software system or application since in manual scripted testing; the test cases are created beforehand.

- The primary sources of information to the testers are functional design specifications, requirements documents etc and so on.

- To make the testing more effective, the testers are free to use supplementary sources of information to increase their knowledge of the software system or application by rigorous discussions with the development team.

- Manual scripted testing is used in situations or programs where a waterfall methodology along with the V-Model has been implemented.

- Apart from waterfall and v model methodology, this approach can also be used for projects where requirements and specifications are frozen and likelihood of modifications in those requirements and specifications is very less and this is also suitable for the situations where safety and regulatory situations demand proof of testing.

- Generally, this manual testing approach is considered old but, it is quite relevant in this current era of market driven applications.

The best methodology is mixing manual testing and automated testing together and using it for exploratory testing.