The present review paper describes the advances in materials, mechanisms, and techniques for humidity sensing along with their applications in terms of parameters, utility, durability, and spectrum. Advances in different types of humidity sensing materials are described along with their processing techniques, significance in humidity sensing properties, and applications. The newer application for the use of humidity sensors i.e. monitoring of respiration, metabolic rate, quality of organic solvents, packaging, power plants, agriculture practices, and forensic cases was also explained with suitable illustrations and current references. Although humidity sensing is a very old analytical tool but still suffers from several challenges for appropriate applications. In conclusion, a road map for the nexus between materials science, technology, applications, and existing challenges are presented about humidity sensors.