Brown dwarfs are objects with masses between that of stars and planets. Unlike stars, these objects have no sustained energy source and cool as they age. One such cool brown dwarf has been discovered as a companion to a nearby star. The spectrum of this object is similar to that of Jupiter. Single brown dwarfs have been detected in stellar nurseries. Ongoing and planned efforts, from both ground and space, will enable astronomers to decisively determine the population of these elusive and dim objects. This article provides a brief review of advances in the detection of brown dwarfs focusing on the observational data and brown dwarfs that are cooler than stars.