ok, im typing this STRAIGHT from my bio book .. hope this helps.
QUOTE
Salts are compounds that release ions other than H+ and OH- in solution. Salts and water often form when an acid and a base interact. Depending on a solution's pH, salts are able to dissolve easily.
In general, we say that a substance is dissolved after water molecules cluster around ions or molecules of it and thereby keep them dispersed in fluid. Such clusters are called "spheres of hydration". The spheres of hydration can be formed in the same way when pouring table salt into a cup of water, which keeps the ions (salt) completly disperesed in the fluid (water).
i hope that helps ...