Programming terms, with explanations.

Programming terms

Variables
Variables are used to hold data when the program runs. You can think of a variable as rather like a box with a name on it. You can put data into the box, move it to another box, or change it.
Before a variable is used it should be declared so the program knows the name of the variable, the type of data expected to be kept there and how much of the program can use the variable.

Input and output
A program needs to input to get information or control from the user. The program then uses this impact to produce the required results.
Input could be a number typed into a text box that is then used by a calculation to work out a result.

Subroutines
Programs usually have subroutines to structure the code into small sections. Each subroutine is there for a particular part of the program.
Modern programs naturally structure themselves into subroutines, as a new one is created every time an event handler is added to a control.

Annotations

Professional software developers always annotate their code when writing programs to allow for maintenance. Annotations are comments written into the code to explain what parts of the program are there for.

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