A more thorough explanation:

Trust res, also known as trust corpus, principal, subject matter, or trust property, refers to the property that is transferred into a trust. The term "corpus" comes from Latin and means "body." In the context of a trust, the trust corpus is the "body" of the trust, or the property that is the focus of the trust.

For example, if a person creates a trust and transfers their house, car, and savings account into the trust, those assets would be considered the trust res. The trustee would be responsible for managing and distributing those assets according to the terms of the trust.

It's important to note that the trust res should be kept separate from the trustee's personal property. This ensures that the assets in the trust are protected and managed solely for the benefit of the trust's beneficiaries.