All the money that comes out of our hands is called "expenses". Just as there are different categories of income, there are many categories of expenses and it is very important to understand the difference between them.

 Here are the main expense categories:

a) Necessary expenses:  what one buys for survive and maintain their standard of living; Which it is irreplaceable and necessary.
b) Unnecessary expenses: what is replaceable and desirable, but not necessary.

In relation to their periodicity, the expenses they can also be:

c) Regular expenses: what one buys frequently or what one will need again.
d) Irregular expenses: what one buys from from time to time on an unscheduled basis.

Budgeting includes planning when and how much to spend on these types of expenses based on their relative importance.