The Do...Loop allows you to execute a block of statements an indefinite number of times. The variations of the Do...Loop are Do While, Do Until, Do Loop While, and Do Loop Until.
Do While
Do While|Until condition
statement(s)...
[Exit Do]
statement(s)...
Loop
Do Until
Do Until condition
statement(s)...
Loop
Do Loop While
Do
statements...
Loop While condition
Do Loop Until
Do
statements...
Loop Until condition
Do While and Do Until check the condition before entering the loop, thus the block of statements inside the loop are only executed when those conditions are met. Do Loop While and Do Loop Until check the condition after having executed the block of statements thereby guaranteeing that the block of statements is executed at least once.