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 |