To be "sealed" within the Church of Jesus Christ of Latter-day Saints (commonly called the "Mormon" church) means that your relationship may extend beyond the grave into the eternities. Individuals may be "sealed" to their spouse, parents, or children, allowing their family relationships to continue in heaven. So if you are sealed to your husband or wife, your marriage will continue in heaven rather than "until death do you part".The sealing ceremony is one of the most sacred within the church, and also the most simple. It is the highest ceremony most church members will ever participate in. Those being sealed will wear all white and kneel across from each other at an altar in a specially designated "sealing room" in a temple and will have a blessing pronounced upon them by an ordained "sealer". If one or more of the individuals being sealed are deceased, living people may serve as proxy for them. Most temples offer a larger sealing room for couples choosing to have a temple sealing ceremony in place of a traditional wedding ceremony which will allow them to invite a select few family and friends, providing those guests are also devout members of the faith.For more information see the following links:Photograph of a sealing room in the Payson Utah TemplePhotograph of a sealing room in the Star Valley Wyoming Templeofficial church teaching about temple sealings