An information property list is a specialized type of property list that contains configuration data for a bundle. The keys and values in the file describe the various behaviors and configuration options you want applied to your bundle. An Xcode project template contains an information property list file (the Info.plist file) with an initial set of keys and appropriate default values. You can edit the file to change or add keys and values, as appropriate for your project.
For details on the keys you can edit, go to Information Property List.