The word "sweet" is used to indicate something which has similar taste characteristics as sugar, honey etc. Many people are said to have a sweet-tooth. It is this category of people who love to binge on sweets, chocolates etc. Having sweets is often a gratifying experience for many people. Generally, on any occasion, we traditionally greet our near and dear ones by gifting them sweets and spreading happiness.
The word "sweet" can also be sued to indicate something that sounds pleasing and soft to the ear. People are said to have a sweet or mellifluous voice, if their voice is sweet enough to strike a chord in the hearts of the listeners. Very few people are gifted with a sweet voice. A person is called sweet if his or her behavior and mannerisms are adorable. Sweet people have a nice nature and a very clear heart. They don't despise anyone and don't harbor useless grudges against people.