The Holder is an object type which allows you to contain, carry or show any amount of objects within itself. Holders can be accessed by action-tapping (spacebar) next to it, or when tapped on within another Holder.
A single Holder will always show the same content across the world, whereever and whenever it's placed, and the Holder along with its contents can be viewed (unless the Holder specifies an item needed to view its contents) and collected by other players. Only the creator of the Holder is able to change the contents of the same, including the location of any content in the Holder. Other players may only take objects out of their places within the Holder (if they do not have the correct attributes checked for either the individual object or the entire Holder itself), but not change the Holder's content and positioning globally.
When logged in, a Holder can be set as a Travel Holder via the bottom left menu, where the chosen Holder will be available for the user which has set it to view and use almost any content available within the Holder in any Area they visit. The contents usable in a Travel Holder are limited to only object types which do not feature gameplay-changing attributes, those being Writable, Readables, Bodies, Holders, Mediums, Music, Sounds, Place Names, Viewables, Helpers and Dynamics. Attempting to use other object types in a Travel Holder will result in a screen warning you on which objects the Travel Holder allows you to use. You can opt the Holder out as a Travel Holder by pressing the [X] button to the right of "Travel Holder" in the bottom left menu, where you can select a new Holder as a Travel Holder.