There are 3 main programming constructs that you need to be able to define and recognise.  These are:

Sequence

A block of instructions are executed one after another in turn.

Selection

A block of instructions may or may not execute depending on the outcome of a test.  Sometimes called branching because a program takes one execution path or another.  For example, with the IF THEN construct or the SELECT CASE construct.

Iteration

A block of instructions is executed repeatedly until an exit condition is met.  Sometimes called looping. For example, with the FOR NEXT construct or the DO WHILE construct.

NOTE:
The DO WHILE construct comes in a number of syntactical forms depending on the programming language.