<Cstdlib> Header File use for what function?

Question

Using in Function.

Answer 1

The C standard library is mostly used for dynamic memory allocation with malloc, calloc and realloc, but also for utility like rand and exit. Here's more information:
http://www.cplusplus.com/reference/cstdlib/

Answer 2

cstdlib is same like C Language's <stdlib.h> which is used for dynamic memory allocation with malloc, calloc, free...