TASTE

Taste, also known as gustation, is the human sense which drives our appetite and protects us from ingesting poisons.  We taste with sensory organs [that detect chemicals] called taste buds which are located on our tongue. 

Our taste buds are limited to sensing only five distinct tastes:
salt, sweet, sour, bitter, & umami. 

It is important to note that we have taste buds spread all over our tongues to differentiate the five tastes, but we perceive these tastes to have a more localized effect.  For instance, we perceive sourness on the outer sides of our tongue, bitterness on the back, sweetness and saltiness on the tip, and umami throughout.