Electronic inhomogeneities in graphene prevent us from precisely accessing its Dirac point and related physics. One rather gets electron and hole puddles due to this disorder, primarily arising from charge of the defects near the graphene-dielectric interface. The resultant potential inhomogeneity in graphene is also dependent on the screening of the defect potential by graphene carriers with the screening length strongly dependent on the carrier density. Thus the electron inhomogenieties are expected to evolve significantly even with fixed interface defects. In this talk I plan to discuss our recent studies on the electronic inhomogeneities in graphene using scanning tunneling microscopy and spectroscopy (STM/S). We measure local tunnel spectra and conductance maps as a function of back-gate voltage, which controls the carrier density. The local spectra, by way of tip-gating effect, give the variation in local Fermi energy, and the conductance maps explicitly probe the evolution of electronic inhomogeneity, with the back-gate voltage. Finally, both point to a role played by interface states in dictating the local graphene-potential in addition to the carrier density dependent screening length which, at least partially, dictates the length scale of the inhomogeneities. Understanding the physics and chemistry of the interface defects in graphene devices can help us engineer the interfaces for memory applications.