Difference between skilled and Professional is skilled is you knowledge and Professional is you way how to work with people.

The term refers to their skill in: Their knowledge of the Law - Their application of that knowledge - The ability to gather relevant evidence - Their ability in utilitzing their iinterrogation skills and techniques - Their conviction rate.

One skilled in botany; one versed in the knowledge of plants.

he should be good at personality,educated,skilled,good knowledge,active,courtesy,knowledge of the product etc.....

What makes a skilled hacker is the amount of knowledge he has and how good his creativity is, imagine playing chess against a skilled and clever player rather then playing chess with an unskilled player.