Statements in JScript are normally executed sequentially in the order in which they appear in the script. This is called sequential execution and is the default direction of program flow.
An alternative to sequential execution transfers the program flow to another part of a script as a result of conditions that a script encounters. That is, instead of executing the next statement in the sequence, a statement at another location is executed. Another alternative is called iteration, which involves repeating the same sequence of statements multiple times. Iteration is frequently achieved using loops.