Qualifiers or Modifier in C Qualifiers(Modifier) is used in c programming to modify the property of the variable. In C programming Qualifiers(Modifier) there are 5 group of qualifiers(Modifier) 1st group is having 5 types auto, register, static, extern, typedef. 2 nd is having 2 typessigned, unsigned. 3 rd one is having again 2 types Short, long. 4 th one is Constant 5 th is volatile. Group Qualifiers(Modifier) Default Qualifiers(Modifier) 1 auto, register, static, extern, typedef auto 2 signed, unsigned signed 3 Short, long Not Short,not long 4 Const Not Const 5 Volatile Not Volatile Auto It defines the storage class of a variable. However, since the default for local variables is auto , you don't normally need to manually specify it. Register Variables which are most frequently used in a C program can be put in registers using register keyword Local variable are stored in register instead of RAM. Static Static defined local variables d