1)  What is Automation ?
A)   In general, it is the process of implementing particular work automatically by using a machine, to reduce the need of human work in the production of goods and services...
2)  What is meant by Automation in software testing ?
A)   It is a process of testing an application(executing the tests, comparing expected and actual results under some controlled conditions and generating the reports) automatically by using a 'Tool' to reduce the need of human effort.  This tool may be Selenium / QTP / RFT / SilkTest etc...
3) Why do we need automation in software testing ?
A)  Humans can do mistakes...  If a work is to be done several times(repetitive), then, we may skip some work intentionally(purposely) or unintentionally(by mistake) due to time pressure, boring task, etc.. Inorder to overcome these problems 'automation testing' has been introduced to reduce manual task, to save cost and time, to improve accuracy, to perform repetitive execution of tests, to customize defect reporting,etc., and hence automation is needed, as it replaces human with great features...
4)  When to do automation testing ?
A)   It is not always advantageous to automate test cases.. We can do automation,

• When the application is stable.  
• For long term projects.
• When you have lot of regression work.
• When the scenario is easily debuggable.

5)  Which type of testing can be Automated ?
A)  We can automate Regression testing, Functional testing, Stress testing, Performance testing, Load testing, Smoke testing, Compatibility testing, Data-Driven testing etc..
6)  What are the advantages and disadvantages of Automation Testing ?
A)   Advantages :

• Reduces human resources.
• Using an automation tool, test scripts can be executed faster when compared to manual execution and hence saves time.
• Repeatable execution of tests may lead to make mistakes when it is done manually, but, when we automate the same task, accuracy will be improved.
• Test cases can be reused in various versions of software which saves time and cost. 

    Disadvantages:

• Unemployment rate increases as machine replaces human..
• It is not so easy to write automation test scripts, it requires skilled and experienced resources.
• We cannot automate everything as it is advantageous only for repeatable and reusable test cases. 
• Initial cost for automation is very high unless it is open source.
• Debugging skills should be high otherwise its effect will be dangerous (mainly it kills time, so, we cannot reach dead-line).

 7)  Name some test automation tools ...

• Selenium (Open Source)
• HP QuickTest Professional (Commercial)
• IBM Rational Functional Tester (Commercial)
• HP WinRunner (Commercial)
• SilkTest (Commercial)
• HTTP Test Tool (Open Source)
• WATIR (Open Source)
• Maveryx (Open Source)
• eggPlant (Commercial)