WGS 84 (that spelling) is the name of an ellipsoid (EPSG::7030), the name of a geodetic coordinate reference system (EPSG::4326), and the alias of a datum (EPSG::6326), official name World Geodetic System 1984. WGS84 (no space) is the alias of the ellipsoid (EPSG::7030). WGS 84 is most commonly used to describe the coordinate reference system.

Scope: Horizontal component of 3D system. Used by the GPS satellite navigation system and for NATO military geodetic surveying.

Definition: Well Known Text (WKT)

GEODCRS["WGS 84",
  DATUM["World Geodetic System 1984",
    ELLIPSOID["WGS 84",6378137,298.257223563,LENGTHUNIT["metre",1.0]]],
  CS[ellipsoidal,2],
    AXIS["latitude",north,ORDER[1]],
    AXIS["longitude",east,ORDER[2]],
    ANGLEUNIT["degree",0.01745329252],
  ID["EPSG",4326]]

Ref: https://www.epsg-registry.org/export.htm?wkt=urn:ogc:def:crs:EPSG::4326