The article provides overview on the history, conceptuality, and spectral efficiency of orthogonal frequency division multiplexing (OFDM). OFDM is described as a multi-carrier transmission technique which discovered in mid-1960s, and use for in developing effective wireless data transfer. It is recognized as an effective transmission technique for high speed bi-directional wireless data transfer. The three basic standard used OFDM includes WiMAX, DAB (Digital Audio Broadcasting), and DVB-T (Digital Video Broadcasting - Terrestrial). It reveals that OFDM transmit data in many carriers through ranges of 50-1000. Fast Fourier transform (FFT) algorithm and integrated circuit implementation modulator play an influential role towards effective OFDM amplitude spectrum modulation.