A family group sheet is where you record an entire family. Lets say you want to fill out a family group sheet for your great grandparents. It will have the husband and wife with their vital information. It will also show the names of their parents. Then it will list each of their children with their vital information. Below is an example of a family group sheet from Ancestry.com. The only difference between this and a traditional one is it shows a timeline of the persons’ life. It also shows if there were more than one spouse and children from that marriage.
(click on the image to enlarge)