An armature is a system of bones used for animating or deforming a mesh. Use this tag for questions pertaining to armatures.
An armature in Blender can be thought of as similar to the armature of a real skeleton, and just like a real skeleton an armature can consist of many bones. These bones can be moved around and anything that they are attached to or associated with will move and deform in a similar way.
An “armature” is a type of object used for rigging. A rig is the controls and strings that move a marionette (puppet). Armature object borrows many ideas from real-world skeletons.
Armatures at The Blender Manual