what is identity theft?

Google is a great resource and search engine. When I enter that query into Google, I received thousands of replies.

Here's the US DOJ website link to their discussion on Identity Theft:
http://www.justice.gov/criminal-fraud/identity-theft/identity-theft-and-identity-fraud

Furthermore, doing a query using Wikipedia, it also outlines what Identity Theft is. Here's the link:
https://en.wikipedia.org/wiki/Identity_theft