Every object in Neos exists as a slot. A slot is a container for Components, which add additional behavior to slots. Every slot has a transformation (a translation, rotation, and scale) associated with it, which define its behavior and orientation in Neos' 3D coordinate space. For example, a slot with a MeshRenderer component will render a model, and scaling that slot will scale the rendered model.
Slots can be contained in other slots. A slot is a child if it is contained within another slot; that slot is its parent. A child slot's transformation is relative to its parent, so even though a child slot might specify no transformation, in global space it may be rotated or scaled because its parents are. Thus, a child's transform is called "local".
Every world has a root slot under which everything else is placed. The resulting tree of slots is called the hierarchy.
Slots can be browsed through and examined in the Scene Inspector.