A trust is an entity established to hold property (both real-estate and personal property, like financial assets), with directions for how to administer the property. The person who establishes a Trust is the Grantor or Settlor, the person who administers the Trust is the Trustee, and the people who are intended to benefit from the Trust are called Beneficiaries. 

Trusts are often used to hold property during a person's lifetime, and direct how the property is to be held and used, or distributed after the person dies. In that case, one objective of the Trust is to provide for the transfer of the property, after the person dies, without the property going through the Probate process. 

Another common use of a Trust is to set aside property for the benefit of a  a person, in a manner which prevents them from losing government benefits the person may receive. One objective is to enable the person to have their special needs assisted by the Trust property, while government benefits such as Medicaid, Social Security Supplemental Income or other means tested programs provide for the persons medical, shelter, food, clothing and personal care needs. 

The document which establishes a Trust must be carefully drafted to achieve the goals and objections of the Settlor and the Beneficiary. An attorney who is familiar with setting up Trusts should always be consulted.