Bohr supposed that the electrons orbited the nucleus in circular orbits, Schrödinger's model uses a wave function (defined by the Greek letter Psi) to describe the electrons, this function doesn't explicitly give the information on the electrons, it gives the information in terms of probability density.
In Schrödinger's model there is always a small chance that the electrons are in any possible configuration because it describes the atom as a superposition of different states, each with it's own probability. It is not until you observe the atom that you can find the position or speed of an electron.
