Marker

Markers are entitites intended for use in data packs and map-making. They can only be created with the /summon command.

Behavior
Markers are intended to have minimal behavior. Markers do not move, do not take damage, do not make sounds, and cannot be given status effects.

Markers do not cause any updates. Markers only exist on the server side, so they do not render. Using the debug key combination, which normally draws the hitboxes of all visible entities, does not show a hitbox for a marker. Using while aiming at a marker does not copy the entity data to the clipboard. They do not count towards the E-value (total amount of entities) listed on the debug screen. Markers do not obstruct the placement of blocks, nor do they push players or other entties away from their own position.

Entity data
Markers have entity data associated with them that contain various properties of the entity.