A ketuba is a Jewish marriage contract that outlines the mutual duties between a man and a wife. This is one of the most important documents in Jewish life, and it is not permitted for a husband and wife to live together without one (if your ketuba is lost and stolen, it is essential to consult a rabbi so it can be replaced immediately.)
Many ketubot (plural for ketuba) are beautifully designed and some people frame them and put them on the wall of their homes. However, a ketuba that is simple and unadorned is no less valid than a fancy one. More important than the decorative aspects of the ketuba are the details in writing the ketuba that render it kosher. The ketuba must be written correctly with every letter distinct. A professional Jewish scribe called a sofer is knowledgeable in this area, and he should be consulted in the writing of a kosher ketuba. A ketuba must be signed by two witnesses, however, they need not be the same witnesses who are present at the chuppa (wedding ceremony.)
The ketuba is a contract stipulating what a man must provide for his wife and vice versa. A husband is to provide his wife with food, clothing, and he is to pay for meddical care if she gets sick. He is not allowed to withold marital relations from her. If she dies or they divorce, he is to pay a sum of money, and is expected to pay for her burial if she predeceases him. In addition, if he dies, her ketuba money is to be granted to her children before the estate is divided, and she is allowed to live in his home until she remarried or dies.
In return, a woman is supposed to give her husband any wages, gifts, lost objects, or monetary profits she receives. However, the only reason the wife is supposed to give her husband these things is that he is supposed to support her. If a woman decides that she prefers to be self-supporting (as many women who have careers nowadays may want to do), she need not hand her wages over to him. However, a rabbi should be consulted to make such an agreement official.
The Ketuba is read under the marriage canopy before the couple weds. The bride takes it in her hand as a sign of her consent. The contract is read in Aramaic, and few people nowadays can understand it. However, it is essential that a bride and groom understand their mutual responsiblities before they get married, and there are many classes available for engaged couples (usually they learn separately).