Dissolve - Think about how you put sugar into cofee, the sugar disolves into it, so you don't drink sugar pieces.
Solvent - is a substance used to disolve stuff. For example acetone disolves plastic in general, so you do not use it to clean your camera.
Solute - is a disolved substance. For example sugar in the cofee after it's been dissolved.
Chemical reaction - When you mix 2 chemical elements that have an action one to another, a chemical reaction happens. For example if you put Sodium in water, it releases hidrogen and heat (often the hidrogen ignites)
Concentrated - if you put too much sugar in your cofee, you say it's too concentrated.
Saturated - the moment you add more sugar to the cofee, and it just does not dissolve, you say the cofee is saturated with sugar.
Dilution - Reducing the concentration of a chemica. Adding more cofee to a saturated cup, is diluting it.
Crystallization - is the natural or artificial process of
formation of solid crystals in nature or lab. For example the formation of ice crystals. More on the wikipedia page
HERE.