A beneficiary is a person entitled to the prudent loyalty of the fiduciary owner if money or other property transferred in trust.
A private trust for private purposes has one or more named beneficiaries or persons drawn from a class that closes when the trust is constituted. These trusts are generational, in the sense that the trust is only allowed to continue under the law (something called The Rule Against Perpetuities) for “lives in being plus 21 years”, i.e. a private trust can only continue for one generation.
A social trust for social purposes, such as a Pension or an Endowment, as for a university or a charitable foundation, has an evergreen population drawn from an open class of current and future beneficiaries that ongoing across the generations. These trusts are intergenerational, in that they are given special standing under the law to be ongoing in perpetuity.
This is an important distinction for determining the fiduciary purposes and powers of institutions of intergenerational fiduciary duty, and how they differ from the more limited purposes and powers of fiduciary owners of private generational trusts.