Though of not much economic importance the Ferns do have amazing properties. They can remove some toxic elements from the atmosphere. They are used as biofertilizers, food, and medicine. It is also used for ornamental purposes and for remediating contaminated soil. Some fern species are found inland and few in water. Bracken (Pteridium aquilinum) is a form of land fern. Azolla filiculoidesisa typical water fern. They are available worldwide. They can fix nitrogen and make a significant input to the nitrogen nutrition for wheat and rice. Wide applications in the countryside make it one of the attractive forms of fern. The name “Azolla” is derived from the Greek word azo (to dry) and allyo (to kill) meaning that the plant dies when it dries. The genus Azolla established by J. B. Lamark as early as 1783 was placed in the family “Salvinaceae” of the order Salviniales. Many kinds of azollas are found spread across the globe and almost 40 kinds have been recognized distinct. The genus is further categorized into two sub-genera termed Euazolla and Rhizosperma. Azolla imbricate Nakai has been reported as an independent species instead of a sub-species of Azolla pinnata. Azolla is one of the aquatic Pteridophyte that may be used as animal food, as green manure. It can also be used as a biofertilizer, for increasing soil fertility, bioremediation of wastewater, and reclamation of saline soils. Due to its high nutritional values and protein content, Azolla is suitable for human consumption and as a feed supplement for a variety of animals like fish, ducks, cattle, poultry, etc., to reduce feed cost. It also finds use in biogas and hydrogen production, as space food, in controlling weeds and mosquitoes. With so many applications and its potential in soil remediation for our country, the Azollas are least applied practically and are available in abundance and goes as waste. The agricultural scientists need to give awareness about this species to our farmers, fisherman, and agricultural operators. The book is comprehensive and needs of the hour. This will certainly bring Azolla Activists, researchers, and agriculturalists, together and provide seed for furthering its applications.