Money is earned through:
a. Exchanging your time (time and/or manual labour). This is often in the form of full-time, part-time or contract employment. This appeals to individuals that like stability, predictability and minimal financial stress through a regular pay cheque.
b. Exchanging your ideas (sharing the value you create). Includes operating as a consultant, inventor, author, speaker, and entertainer.
c. Creating something new by managing resources and risks to create value (business). This category is attractive to entrepreneurial types who like to blaze their own trails and/or be the masters of their own domains.
Any indiviual can earn their income from any one or combination of the above sources depending on their personal circumstances and level of ambition.