Today, Test Automation is considered as one of the most trending term in the field of software testing, as it is considered as one of the most efficient as well as effective software methodology, making the overall software development/testing life cycle better and taking it to some different level. These days as software testing is moving towards automation, most of the software testers as well as QAs are switching themselves from Manual testing to Automated testing.

Some of the reasons, why automation testing is considered as one of the trending methodology and has a vital scope:

 - Automation testing saves time as well as money.
 - It is considered as cost effective method,
 - Increases Test Coverage,
 - Makes testing more accurate,
 - Better Execution control,
 - Provides better and concise results,
 - Optimized resource usage, etc.

All these reasons make automation testing more effective as well as more efficient, resulting in better test outputs.
Depending upon the [functionalities][1], there are various good Automation testing tools for software testing. It totally depends upon the need and requirement of the tester, say for example, some needs Web test automation, some needs to automate Database testing or Cross-Browser testing, etc. Some of the best and widely used Test Automation tools preferred by the testers & QAs, which can offer a long term career are:
 
1. Selenium, 

2. TestingWhiz, 

3. Watir, 

4. Ranorex, 

5. Sahi, etc.


  [1]: http://www.testing-whiz.com/solutions