Scotch, whiskey, bourbon, tequila, most any spirit really, will have unique characteristics. Tasters take note of 3 main areas, the nose (the aromas of the spirits as they leach from the liquid), the taste (the initial flavors that the spirit imparts), and the finish (the flavors that are left lingering on the tongue). Everyone has a unique palate, so what you taste and smell will be different than me. It takes a little practice to be able to put words to flavors, but paying attention as you sip is the best way to start.