In this paper a review of the technology of production and applications of water glasses was presented as well as their definition and the n methods of their identification and description. Mainly sodium water glasses were presented because they have much wider area of applications than other types of alkaline silicates. It was shown that many scientific centers in the word are developing technologies of production of silicates and their water solutions using new ideas as well as by modifying the technologies earlier proven effective. Among the range of applications of sodium water glasses the problems of water purification (lowering water hardness), anti-corrosion protection of water pipelines were emphasized along with the characteristics of silicate inhibitors and the attempt to elucidate the mechanism of their anti-corrosion action not only on steel but also on other materials. The uses of sodium silicates as packing and form making masses as well as other applications of water glasses were also discussed. For the attempt to elucidate the action mechanism of silicates, the second part of this paper was prepared in which the methods of determination of molecular composition of sodium silicates water solutions were presented.