Compressive sensing is a relatively new technique in the signal processing field which allows acquiring signals while taking few samples. It works on two principles: sparsity, which pertains to the signals of interest, and incoherence, which pertains to the sensing modality. Since, in conventional system all signals follow the Nyquist criteria, in which the sampling rate must be at least twice the maximum frequency of modulating signal. But, in this new concept we can recover the signal below the Nyquist rate. This paper presents the basic concept of compressive sensing and area of applications, where we can apply this technique.