A will is a traditional legal document which:

• Names individuals (or charitable organizations) who will receive your assets after your death, either by outright gift or in a trust.
• Nominates an executor who will be appointed and supervised by the probate court to manage your estate; pay your debts, expenses and taxes; and distribute your estate according to the instructions in your will.
• Nominates guardians for your minor children.

Most assets in your name alone at your death will be subject to your will. Some exceptions include securities accounts and bank accounts that have designated beneficiaries, life insurance policies, IRAs and other tax-deferred retirement plans, and some annuities.

A trust is an arrangement in which money, property, assets are managed and owned by one party, for later benefit of another. 

The Settlor is the creator of the trust. The settlor entrusts the money, property, assets etc to people of his choice. The trustees are the legal owners of the property within the trust - better known as trust property (or trust corpus). However they hold the ownership of the trust with the benefit of the beneficiary. The beneficiary is the third party. This is the person or party that will receive all of the trust property when trust comes to term.

It is a legal document that can, in some cases, partially substitute for a will. With a revocable living trust (also known as a revocable inter vivos trust or grantor trust), your assets are put into the trust, administered for your benefit during your lifetime and transferred to your beneficiaries when you die—all without the need for court involvement.

Most people name themselves as the trustee in charge of managing their living trust’s assets. By naming yourself as trustee, you can remain in control of the assets during your lifetime. In addition, you can revoke or change any terms of the trust at any time as long as you are still competent. (The terms of the trust become irrevocable when you die.)

In your trust agreement, you will also name a successor trustee (a person or institution) who will take over as the trustee and manage the trust’s assets if you should ever become unable to do so. Your successor trustee would also take over the management and distribution of your assets when you die.

A living trust does not, however, remove all need for a will. Generally, you would still need a will—known as a pour over will—to cover any assets that have not been transferred to the trust.

If you set up a living trust, for example, the trustee will provide the necessary management of those assets held in trust. You should also consider setting up a durable power of attorney for property management to handle limited financial transactions and to deal with assets that may not have been transferred to your living trust. By doing this, you designate an agent or attorney-in-fact to make financial decisions and manage your assets on your behalf if you become unable to do so.

And by setting up an advance health care directive/durable power of attorney for health care, you can also designate an attorney-in-fact to make health care decisions for you if you ever become unable to make such decisions.

In addition, this legal document can contain your wishes concerning such matters as life-sustaining treatment and other health care issues and instructions concerning organ donation, disposition of remains and your funeral.

Estate taxes are imposed upon estates that have a net value of $2 million or more. That amount will increase to $3.5 million in 2009. In 2010, the estate tax will disappear completely.

Then, unless Congress passes an extension, the exemption will revert back to $1 million in 2011. For estates that approach or exceed these amounts, significant estate taxes can be saved by proper estate planning, usually before your death or, for couples, before one of you dies.

Keep in mind that tax laws often change. And estate planning for tax purposes must take into account not only estate taxes, but also income, capital gains, gift, property and generation-skipping taxes as well.