Google Webmasters and Indexing

[SeoDezin]

How can we check either our website is indexed or not ? Moreover either this tool is helpful or not in checking the penalization of a website ?

[Yuga]

A page is indexed by Google if it has been visited by the Google crawler ("Googlebot"), analyzed for content and meaning, and stored in the Google index. While most pages are crawled before indexing, Google may also index pages without access to their content (for example, if a page is blocked by a robots