Currently, from the viewpoint of modern Physics, everything can be described (as far as the Four Fundamental Forces), as a Field.

First, we have to define a Field: A field, is a physical quantity, which is present all throughout space-time, with a value for every point in spacetime, and can be on average zero, or non-zero in any given region, and contains waves.If a field is non-zero, it's effects may become physically visible.