Societies work in a manner similar to trusts. That is why these two terms are often used interchangeably. However, both entities are different from each other. The Societies Registration Act, 1860 govrns societies in India. On the other hand, private trusts come under the purview of Indian Trust Act, 1882. Apart from the governing acts, here are some more key differences between the two.
Society needs a minimum of seven members, trust needs two. Trusts don't need a separate all India registration, societies do. Voting system governs a society, but one person can control a trust. Amendments are easy in case of trusts, not so in case of societies. Trust may be revoked with ease, but it is more difficult in case of societies. A trust can have general objectives, but a society cannot. It needs to have specific objectives. It is possible to make a family member the trustee. But, it is usually not possible in case of societies. A trust works as per the trust deed. A society works as per its MoA and regulations.
Moreover, the society may have any other purpose if the state law allows it.