The document discusses while() and do while() loops in C. It provides examples of using while() loops to calculate factorials and Fibonacci sequences. Do while() loops are similar but always execute the code block at least once. The key differences between while(), do while(), and for() loops are explained. Examples are given to count digits and find min/max digits using do while loops. Finally, the syntax and use of switch statements in C are covered with examples to select colors and print day of week names.