What distinguishes an "inter vivos" trust from other types of trusts?

An inter vivos trust is defined by its creation during the lifetime of the person who establishes it, known as the grantor. This is a key distinguishing feature that sets it apart from other types of trusts, such as testamentary trusts, which are established through a will and take effect only after the grantor's death. By being formed while the grantor is still alive, an inter vivos trust allows for immediate management and distribution of assets, reflecting the grantor's intentions for their property while they can actively oversee its administration.

The focus on its creation during the grantor's lifetime highlights the trust's role in estate planning, providing benefits such as avoiding probate and potentially offering tax advantages. Thus, the correct answer underscores the foundational aspect of inter vivos trusts in estate planning and asset management.