Selenium Interview Questions

Below are the few commonly asked Selenium Interview Questions
What is Selenium?
Selenium is a suite of tools for browser automation. It is composed of “IDE”, a recording and play back mechanism, “WebDriver” and    remote control “RC” which provides APIs for browser automation in variety of languages and “Grid”, which allows many tests using APIs to be run in parallel. The recorded tests can be imported in most languages like html, Java , .net , perl , ruby etc. The exported test can be run in any browser and any platform using selenium remote control “RC”
 What are the components of selenium ?
Selenium IDE – Plugin to Firefox to record and play test in Firefox and also export tests in different languages. The most appealing format is the html test case which seems to be based on fit html
Selenium RC- Allows playing of exported test in different platform/OS
Selenium Grid – Allows to control lots of selenium machines(you typically don’t need this only for load test -and hence may ignore it).
What are the capabilities of Selenium WebDriver or Google WebDriver or Selenium 2.0? 
Capabilities of Selenium WebDriver or Google WebDriver or Selenium 2.0 are:
One should use WebDriver when requiring improved support for

1. Mult-browser testing including improved functionality for browsers not well-supported by Selenium-1.0.
2. Handling multiple frames, multiple browser windows, pop-ups, and alerts.
3. Page navigation.
4. Drag-and-drop.
5. AJAX-based UI elements.

Which are the browsers supported by Selenium RC?
Browsers supported by Selenium RC are:

1. Firefox
2. Mock
3. Firefoxproxy
4. pifirefox
5. iexploreproxy
6. iexplore
7. firefox3
8. Safari proxy
9. Google chrome
10. conqueror
11. firefox2
12. safari
13. piiexplore
14. firefoxchrome
15. Opera
16. iehta

What are the Operating Systems supported by Selenium?
Operating Systems supported by Selenium are:
Selenium IDE
Works in Firefox 2+ Start browser, run tests Run tests
Operating Systems Supported:

1. Windows
2. OS X
3. Linux
4. Solaris
5. Others whichever supports Firefox 2+

Selenium Remote Control:
Used for starting browser and run tests
Operating Systems Supported:

1. Windows,
2. OS X
3. Linux
4. Solaris
5. Others

Selenium Core:
Used for running tests
Operating Systems Supported:

1. Windows
2. OS X
3. Linux
4. Solaris
5. Others

What is the difference between assert and Verify Commands?
There are two mechanisms for validating elements that are available on the application under test. The first is assert: this allows the test to check if the element is on the page. If it is not available, then the test will stop on the step that failed. The second is verify: this also allows the test to check whether the element is on the page, but if it isn’t, then the test will carry on executing.
What is the price of Selenium license per server?
Selenium is open source software, released under the Apache 2.0 license and can be downloaded and used without charge.
How much does Selenium license cost per client machine?
Selenium is open source software, released under the Apache 2.0 license and can be downloaded and used without charge.
Where to download Selenium?
Selenium can be downloaded and installed for free from seleniumhq.org