CBSE Class 9 Answered

Crystallization is the process of formation of solid crystals precipitating from a solution, melt or more rarely deposited directly from a gas. Crystallization is also a chemical solid-liquid separation technique, in which mass transfer of a solute from the liquid solution to a pure solid crystalline phase occurs.

Making steel, steel is an example of crystalline. 
Making hard tack candy, making fudge although sugar is considered noncrystalline, you are varying the phases of sugar to include one large sugar crystal to get hard tack and annealing the fudge to avoid the formation of sugar crystals.