Define constant.

Define variable

What is a global variable?

What is a local variable?

What is an identifier?

What is a reserved word/keyword?

What are the differences between constants and variables?

What does 'initialising variables' mean?

How can you use constants to maintain a program?

When naming constants and variable, what should you do?

How can you lay out code to make it more maintainable?

Why should programmers use these programming techniques?