Finish is a common and familiar term often used to describe the taste profile of a particular scotch. To put it simply, the finish of a scotch can be described as the after-taste left in the mouth.
"Short" and "long" are two of the most common words to describe the finish of a scotch. The scotch's finish is how long the flavor impression lasts in your mouth and on your tongue after it is swallowed. This is where the scotch culminates, and the after-taste comes into play.
To observe the finish of the drink, ask yourself these questions: did it last several questions? Was it light-bodied (think the weight of water), medium-bodied (like the weight of milk) or full-bodied (with the consistency of cream)? Can you taste the remnant of the scotch on the back of your mouth and throat? What was your last flavor impression - fruity, smoky, oak? Does the taste persist, or is it short-lived?