In today's scenario there is a rapid growth of wireless communications. This growth has moved the world into the new era of technology where the number of subscribers dependent on mobile phones are increasing at an alarming rate. This paper gives the glimpse of 4G cellular networks. It presents an overall vision of the 4G working, its framework and integration 4G with mobile communication. WiMax and LTE technologies have been discussed in the paper. OFDM and MIMO are the key points in the working of 4G networks. Challenges faced in 4G technology have also been mentioned in the paper.