What does it mean to say one is "wise" in nature? What is the difference between being "wise" and having knowledge?

You infer to saying ‘’wise’’ in nature if the person has shown some wisdom which will stem out of the knowledge he gained.

Having knowledge is the collection of data on a particular subject with facts and information and being wise is making use of the knowledge you gained by consuming the facts and information and then creating your own mental model which eventually will change the outcome out of this experience .