3.1.3 Defining Flow Control

The start/end commands are symbolized as a oval.
The process command is symbolized as a rectangle.
The decision command is symbolized as a diamond .

Source : http://en.wikipedia.org/wiki/Control_flow

3.1.3 Program Flow Control

A sequence in program flow control is a set of instructions that are in order, every order is follows the previous.

(E.G : Go to school - Learn - Leave school )

A selection in program flow control  is a get of if statements that are followed by choice orders.

(E.G : would you like to turn the light off - Yes = light on  No = light off)

A Iteration in program flow control is is a set of instructions that can contain loops and repeating actions.

(E.G: Turn kettle on - Is there any water? - No =  go back to turn kettle on -Yes = Start boiling to 100 degrees - Has Water reached the temperature set? - no go back to start boiling to 100 degrees - yes = turn kettle off)

Source : http://en.wikipedia.org/wiki/Control_flow

3.1.2 Linked Lists

A linked list is quite self explanatory, it is a list attached to another list that gives following list information

for example:

Python does not use linked lists.

sources : http://en.wikipedia.org/wiki/Linked_list