C language : Keywords and Identifiers

                   Keywords and Identifiers in C language

Keywords- 
Keywords are predefined reserved words used in programming that has a special meaning to compiler. Keywords are the  part of Syntax and they cannot be used as an identifier.
For eg. int cash;
Here int is a keyword that indicates cash, which is the variable of integer type.
As C is a case sensitive language all keywords must be written in lowercase.
There are 32 keywords in C programming language-
auto
double
 int
struct
break
if
 else
 long
switch
case
enum
register
typedef
 char
extern
return
union
continue
for
signed
void
do
 static
while
default
 goto
sizeof
volatile
const
float
short
unsigned

Identifier- 

 Identifiers refers to the name given to entities such as variables, functions, structures etc.. Identifier must be unique. They are created to give unique name to a entity to identify it during the execution of a program.
For eg. int cash;
              double accountbalance;
   Here cash and account balance are identifiers.
Also Identifier names must be different from keywords. We cannot use int as an identifier because int is a keyword.