It's a common practice, nowadays, for there to be a wedding rehearsal the night before the wedding. Yes, this is something that your wedding planner can take care of for you as well. They need to ensure that you can use the church or venue for the wedding and restaurant; and that you won't be interrupted by people not involved in the ceremony.

The bride and groom, their parents and their entourage are asked to be present. Each person is asked to stand or walk-in just as they will at the actual event. The difference is, no one is wearing their wedding outfit, just regular clothes. The point of this rehearsal is to have everyone familiar with where they should be at specific points in the wedding, and it familiarizes the entourage on what they should do: the flower girls strewing petals, the giving of the ring, when the couple will read their vows (if they made their own especially).

Dinner usually follows at either the place for the reception or a nearby restaurant. Some couples opt to taste their actual menu during the rehearsal dinner though it's not necessary. Again they go through the steps of the reception but without the actual accessories and of course in a shorter time. No actual cake slicing here!

This gives the families a chance to celebrate the upcoming nuptials in a more relaxed way. This kind of gathering helps form a bond between the new family. As all married couples learn, marriage isn't just about uniting two people; it's about uniting two families.