C language was developed by Dennis Ritchie between 1969-1973 at Bell Labs for use with UNIX OS. It is widely used for application and system software development. A static variable in C is declared inside a function for the function or global scope. A normal variable stores a value while a pointer stores the address of another variable. Calloc() allocates and zero initializes multiple blocks of memory while malloc() allocates a single block. printf() outputs to standard output while sprint() outputs to a character array. Quicksort, radix sort, and merge sort are among the fastest sorting methods in C. Functions are generally preferred over macros except when speed is critical. A stack stores function call information and local variables using FIFO