Keywords are the special words which are used by C language, each keywords has its own meaning and relevance hence, keywords can not be used either as variable or constant names. They are specially used by the compiler for its own purpose. They are used as building blocks of a C program.

These are the Keywords in C

auto	double	inline	static	while
break	else	int	struct
case	enum	long	switch
char	extern	register	typedef
const	float	return	union
continue	for	short	unsigned
default	goto	signed	void
do	if	sizeof	volatile