Relevant is an important concept to be associated with evidence in order for the evidence / information to be accepted by the court.
Relevant indicates that the evidence myst have a relation or connection with the questions of fact to be proved.
Relevant may also lead to the point that existence of the fact is more probable.
For instance in the case of thief, the question of fact may include the identification of the person who stole certain goods.
Evidence / information that shows the goods were found in the house of accused is considered relevant as it answered and make the questions of fact that he is the thief to be more probable.