What is the difference between the local variable and global variable in C?

Following are the uses of a static variable:

• A variable which is declared as static is known as a static variable. The static variable retains its value between multiple function calls.
• Static variables are used because the scope of the static variable is available in the entire program. So, we can access a static variable anywhere in the program.
• The static variable is initially initialized to zero. If we update the value of a variable, then the updated value is assigned.
• The static variable is used as a common value which is shared by all the methods.
• The static variable is initialized only once in the memory heap to reduce the memory usage.

Uses of C function are:

• C functions are used to avoid the rewriting the same code again and again in our program.
• C functions can be called any number of times from any place of our program.
• When a program is divided into functions, then any part of our program can easily be tracked.
• C functions provide the reusability concept, i.e., it breaks the big task into smaller tasks so that it makes the C program more understandable.

A pointer that doesn't refer to any address of value but NULL is known as a NULL pointer. When we assign a '0' value to a pointer of any type, then it becomes a Null pointer.

A pointer which can access all the 16 segments (whole residence memory) of RAM is known as far pointer. A far pointer is a 32-bit pointer that obtains information outside the memory in a given section.