Trusts have not been defined under the Income-tax Act, 1961. Trusts can be broadly classified into three categories : Public trust (charitable / religious trust), Private Trust, Public cum Private trust.
Trust itself is a legal obligation, as the trustees are legally bound to apply the income of the trust in the manner and for the purposes specified by the author of the trust and it includes the following:
Unless all the above requisites are fulfilled, a trust cannot be said to have come into existence.
A formal deed is not necessary to constitute a public trust, still less to constitute a legal obligation binding the trustees. In the case of a dedication to a public trust, what is essential is that there should be an unambiguous expression of intention to divest and an actual divestment of the interest of the donor for the benefit of the charity. Such divestiture can be proved by a written document or by other evidence as it is not necessary that there should be a writing to constitute a valid dedication.