holodeck combines elements of transporter technology with that of replicators, by generating actual matter, as well as projecting force fields to give the objects the illusion of substance. It can be controlled from an exterior control or the interior arch control. This arch can be summoned at any time to change the parameters of a running holoprogram. Matter and energy are interchangeable as such objects created on the holodeck can be either matter or energy. matter replication was primarily used for objects and characters that would be in direct contact with the occupants which gave them an extreme sense of realism. Water, for example, would feel like actual water because on some level, it was, and it could create experiences like odors. This also enabled simple matter to exist outside of the holodeck for brief periods of time (such as snow) before they would lose cohesion without the support of the holodeck grid and revert back to energy.This, however, used an extreme amount of power, and caused repetitive problems to occur in its safe usage. Holodeck walls can generate holographic images that appear to extend for an unlimited distance, seemingly much larger than its own dimensions. In doing so, however, the holodeck is aware only of its users; it does not recognize its own created objects. For example, if a person were to throw a holographic rock at the holodeck's walls, the rock would not be allowed to pass beyond the wall (if it were of replicated matter). It does this by continuously adjusting the projections of the force fields and the use of a force field "treadmill".With this, an individual approaching a wall causes an instant shift away. It can also manipulate light photons, 'lensing' them to make individuals appear further away if two persons were separated in a scenario. The holodeck can change gravity in three dimensions, so occupants don't notice the change.
