Taproots are the big, central roots that some plants have. They are key parts of such plants as all other roots needed for nutrients will grow out of the taproot.
Sometimes these will also be designed to be storage organs for the plant to store nutrients in as well. In such cases, these are often eaten like with carrots and radishes.
Culinarily, taproots are always vegetables. They never have seeds or ovaries in them and are therefore not even botanically fruits.