Hearsay (3)

Comparison between Hearsay and Direct evidence 
Direct evidence is the evidence from the witness who perceived the relevant act himself. 
For instance, X was charged with theft of book from the bookstores. 
Y told Z that he saw X stealing the book. 
The prosecution cannot called Z to testify that Y told him that he saw X stealing the book.
The correct approach is for the prosecution to call Y to give direct evidence of what he saw and believed.