The federal gift and estate tax are really just one tax. The individual exemption amout applies to property you give away during life or leave at your death. In other words, you can transfer, either while you're living or at your death, up to $5.25 million of property tax-free for deaths in 2013. (The exemption amount was $5.12 million for 2012 deaths.)
Most gifts are tax-free, which means they don't count against the personal exemption amount. Only gifts of more than $14,000 per year to any one person or noncharitable institution are taxable. Making gifts of $14,000 or less, however, can yield substantial estate tax savings if you keep at it for several years.
Some gifts are exempt from the gift/estate tax no matter what their amount. For example, if your spouse is a U.S. citizen, you can give your spouse an unlimited amount of property free of gift tax; a noncitizen spouse can receive up to $143,000 (2013 figure) per year tax-free. Any property given to a tax-exempt charity avoids federal gift taxes, and money spent directly for someone's medical bills or school tuition is exempt as well.