What are the types of qualifiers? 

Understanding Qualifiers in Programming: Types and Applications

In programming, there are two types of qualifiers:

1. Storage Class Specifiers: These qualifiers define the scope, lifetime, and initialization of variables. The four types of storage class specifiers are:

• auto: This specifier is used to declare a variable within a block and is automatically destroyed when the block is exited.
• register: This specifier is used to suggest to the compiler that a variable is likely to be heavily used and should be stored in a CPU register for faster access.
• static: This specifier is used to declare a variable that retains its value between function calls and is initialized only once.
• extern: This specifier is used to declare a variable that is defined in another source file.

2. Type Qualifiers: These qualifiers modify the type of the variables and the operations that can be performed on them. The four types of type qualifiers are:

• const: This qualifier is used to declare a variable whose value cannot be modified once it has been initialized.
• volatile: This qualifier is used to declare a variable whose value can be modified by external events, such as hardware interrupts or other threads.
• restrict: This qualifier is used to declare a pointer that is the only way to access a memory location, allowing the compiler to perform optimizations.
• _Atomic: This qualifier is used to declare a variable that can be accessed atomically, meaning that it is guaranteed to be either completely updated or completely unchanged during concurrent access.