Quantum control originated in the mid-1980s as a set of different laser schemesdesigned to manipulate chemical reactions and excite the molecule in specific quantumstates. In the last four decades it has enlarged its scope to optimize any type ofprocess in quantum systems. In this chapter we analyze in a stepwise manner howthe different laser parameters: pulse area, optical phase, duration, timing, frequencyand intensity, affect the dynamics, motivating different quantum control mechanisms.We explain the control setups in simple scenarios that involve a few particles, mostly atrapped ion, a quantum dot or a diatomic molecule. Using examples from our ownpublications, we show how the different control schemes can be used to preparethe system in specific quantum states, or prepare quantum gates, or manipulate theposition and width of the wave function, or control the geometry, photophysics,and photochemistry of the molecule in the excited state. Finally, we give an introductionto the techniques of optimal control theory that allow to generalize and globallyoptimize the dynamics of the system by using a variational approach.