Code is generally executed line by line, in the order the expressions appear. This is called sequential execution. You can, however, change the order in which expressions are executed by using control flow expressions.
For example, you can make decisions about what expressions to execute next using if and case expressions, or repeat a sequence of expressions more than once with loop and for. The following pages describe these expressions in detail, and include examples of how to use them.
Verse has more expressions you can use to change the time flow of a program by executing expressions simultaneously. For more details, see Concurrency.