Microgrids are a new paradigm for energy distribution systems in which generation (from a local energy source or storage device) is coordinated to supply local energy needs while behaving as a sole system. Benefit maximization in a microgrid is directly related with demand reactiveness and optimal allocation of local energy resources. Because those characteristics can be implemented through an Energy Management System (EMS), knowing the elements that conforms it and how they interact is crucial for the development of microgrids. This paper presents a caracterization of the EMS and some insight about the actual state on this subject. This is done to understand the mechanisms that allow efficient EMS implementations, thus shortening the path towards a power distribution microgeneration with higher short-term/mid-term benefits based on microgrid technology.