Particles

In physics, a particle is an object, or body, with only a few degrees-of-freedom, including position, and perhaps orientation in space.

The homogeneity and isotropy of space, being symmetries with respect to translation and rotation, may provide for particle properties such as momentum and angular momentum. These are common to classical mechanics and quantum mechanics. Certain internal degrees-of-freedom provide fixed physical properties, such as (electric) charge, or variable ones, such as spin angular momentum, most of which can only be understood within quantum mechanics.

See also