These just refers to your organizing instruments. For PTO's this is usually two documents:

Contstitution - establishes the organization and provides basic information such as its purpose, name, structure, membership, etc.

Bylaws - the basic rules by which the ogranization operates.

The IRS accepts these just fine without re-titling them "Articles of Organization". They do have some expectations that they contain some specific language, but like ABC123 said, the IRS is very helpful. If you are missing a piece they feel is critical, not only will they tell you - they'll suggest some boilerplate language to fix it.

When I spoke with the IRS person they told me
Association. Non-Profit - Tax ExemptIRS
# 1-877-829-5500. They were very helpful. It's on their website as well.

We are a new PTO and are looking into filing for 501(c)(3) staus. It is my understanding that we first need to file Articles of Incorportion or Articles of Association. Which one should we do? What is the difference?