4G (also known as Beyond 3G), an abbreviation for Fourth-Generation, is a term used to describe the next level of evolution in the field of Wireless communications. A 4G system will offer a complete replacement for existing communication networks and is expected to provide a comprehensive and secure IP based solution where facilities such as voice, data and streamed multimedia will be provided to users on an “Anytime, Anywhere” basis and at much higher data rates compared to previous generations. 3G is used by mobile broadband providers all around the globe, but 4G will provide much faster access to the Internet.

More Information: http://en.wikipedia.org/wiki/4G