A null-terminated byte string, or ntbs, is a character sequence whose highest-addressed element with defined content has the value zero (the terminating null character); no other element in the sequence has the value zero.170
The value of an ntbs is the sequence of values of the elements up to and including the terminating null character.
Many of the objects manipulated by function signatures declared in <cstring> ([c.strings]) are character sequences or ntbss. The size of some of these character sequences is limited by a length value, maintained separately from the character sequence.
A string literal, such as "abc", is a static ntbs.