Diff betw Operating Foundation and Endowment

Can someone explain the difference between operating foundation and endowment ?

The way I understand it Endowment: A fund owned and funded by the organization it is intended to support Operating foundation: Established for the sole purpose of funding an organization, like a museum, zoo, public library, etc. or some on-going research/medical initiative. Not owned by the organization it is intended to support.

Foundation: after being established, not expecting to receive further funding. For charities of an individual or a family; Needs to spend at least 5% of asset to maintain tax-free status; Endowment: public donations, can fundraise on an on-going basis.

If this is for IPS purposes: the 5% spend is salient, not sure if anything else mentioned will be important for L3 purposes. IIRC, there’s also a difference in dependence on funding by the recipient. Endowments often support the recipient’s operating budget, and as such need to at least maintain that funding level. The impact of a shortfall in a foundation’s funding ability may be less damaging.