Keywords are the basic building blocks for programming statement. These are the words whose meaning has already been explained to the C compiler. Keywords also known as reserve words whose meaning cannot change. All keywords written in lower case and cannot be used as a variable names. There are 32 keywords available in C as listed below:
1. auto
2. break
3. case
4. char
5. const
6. continue
7. default
8. do
9. double
10. else
11. enum
12. extern
13. float
14. for
15. goto
16. if
17. int
18. long
19. register
20. return
21. short
22. signed
23. sizeof
24. static
25. struct
26. switch
27. typedef
28. union
29. unsigned
30. void
31. volatile
32. while