Distinguish between the functions islower() and tolower(). (2)
Ans:

islower( ) and tolower( ):
islower(c) is a character testing function defined in ctype.h header file. This
function determines if the passed argument, in this case c, is lowercase. It returns a
nonzero value if true otherwise 0. tolower (c) is a conversion function defined in
ctype.h header file that convert argument c to lowercase.