This would mean that the income in the trust would be used for the benefit of Mr. and Mrs. Robert Smith during the lifetimes of both Mr. and Mrs. Robert Smith. If either Mr. or Mrs. Robert Smith entered a nursing home, the Medicaid department would not consider the assets of the trust to be owned by them. The trust could stipulate that upon the death of Mr. and Mrs. Robert Smith that the assets should go to their two children. If the trust does this, Mr. and Mrs. Robert Smith have avoided probate. Probate refers to the legal process of passing property to one's heirs after one dies.
Probate is costly and delays the actual passing of property by many months.