The Uniform Gifts to Minors Act (UGMA), superseded by the Uniform Transfers to Minors Act (UTMA) in some states, is simply a way for a minor to own property, such as securities. Generally, any adult may act as a custodian of such an account, including a parent or guardian.
The UGMA/UTMA setup is commonly used to give monies to a minor. IRS regulations allows a person to give many thousands of dollars per year to any other person with no tax consequences. If the recipient is a minor, the UGMA provides a way for the minor to own the assets without involving an attorney to establish a special trust. When giving assets to a minor using a UGMA/UTMA, the donor must appoint a custodian (the trustee).
An UGMA/UTMA is a trust like any other trust except that the terms of the trust are set in the state statute instead of being drawn up in a trust document. Should a trustee fail to comply with the terms of the UGMA/UTMA, this would expose the trustee to the same actions as a trustee who fails to comply with the terms of a special drawn-up trust.