A will must usually go through the probate process while a trust does not. With a trust, a person can also be appointed who will step in to manage person’s financial affairs if the person becomes incapacitated. A trust can also protect assets for minor children.
If a person has real estate in multiple states and beneficiaries for those assets are named in a will, the will usually has to go through probate in each state. This may be another reason a person might prefer to use a trust. An estate plan can use a trust to pass the majority of the assets and a will to appoint guardians for children and deal with assets not named in the trust.
Working with an attorney may help a person determine which document would be best for passing most of their assets. For example, if there is a family member with special needs who receives government assistance, getting an inheritance could affect that assistance. If it were placed in a special needs trust, the money could be accessed to help without affecting these benefits. If a person might not manage their inheritance responsibly, constraints could be put on distributions, or the trustee could decide when distributions are made.