That is called an lonic bond.
Ionic bonds are formed between elements with greater than 1.4 electronegative variance and to a lesser extent by first ionization energy variance, such as alkali metals and nonmetal halogens for example. The element of lesser electronegativity, the cation, donates an electron(s) from it's valance shell to the element with the greater electronegativity, the anion, which accepts the electron(s) unto it's valance shell. This bond is extremely strong and has a high melting point but because of waters polar nature this type of bond, usually, not always, disassociates in water.