Null character?

Question

what is the importance of null character at end of strings in c ?

Answer 1

it's added like a last character in all string.its character only...for example,
"hi" has two characters h and i..but actually it has three characters.. h, i and null character... compiler internally uses character called null to terminate string

Answer 2

Ahmed Mamdouh in c, string is considered as char array... termination of string is defined by null character... This null character plays internal role in c++ string headers for which we don't have to worry much...

Answer 3

so it's just to be considered as a string .. not a character .. regarding header functions right ?
another question plz .. why does header has implantation. . it suppose to be just definitions?