An organization is a structure through which people work together to make things happen. Some people enter public service careers because of employment with — or a desire to work with — a specific nonprofit organization.
For example you might admire the work of a nonprofit that has a unique approach and that is getting a lot of media attention, like Harlem Children's Zone or Teach For America.
Additionally, you might have heard that a nonprofit had excellent family-friendly benefits, or received an award for being a great place to work.
Your next steps if you're approaching your career through the lens of "organization" may be to:
Often similar organizations will see each other as competitors — for attention, funding, volunteers. Understanding the ways each organization distinguishes itself from other similar organizations is crucial.