Until the end of the 19th century, vegetable oils were practically not refined and mainly used for technical purposes. Nowadays, the refining of oils has become almost obligatory as the consequence of developing extraction technologies and applying them to manufacture  oils, as well as owing to the use of catalytic methods for hydrogenation (margarine production) and the consumer demand regarding oil  quality. Crude vegetable oils contain varying amounts of non-acylglycerols (non-fatty impurities), generally classified as “gums” or  phospholipids, and of other contaminants such as free fatty acids, metals, pigments, waxes, hydrocarbons, etc. To the group of gums  belong phosphatidic and lysophospatidic acids, their salts with various cations, as well as chemical compounds of phosphatidic acid with  choline, ethanolamine, and inositol. The gums negatively impact, among other things, the colour, flavour, and foaming of oils; therefore, they should be removed in the degumming processes. The present paper is a review of the reference literature dealing with the water and  acid degumming of edible vegetable oils as the first step of refining those oils. Discussed were the principles of technologies and chemical  interpretations of the applied solutions, i.e. water and acid degumming, SOFT and TOP processes, and their modifications. Special  attention was drawn to the physical and chemical properties of components, molecular mechanisms, and to advantages and disadvantages  of the methods applied. Chemical rudiments were explained of the hydration of phosphatidylcholine and phosphatydylinositol, further: of  the restricted hydration of phosphatidilethanolamine and non-hydratable phosphatydyl acid and its salts with Ca, Mg, and Fe cations.  Chemical basics of using various acids and chelating agents (EDTA) in degumming processes were also discussed.