Classical unified field theories describe the properties of the electromagnetic field as a purely geometric phenomenon. Einstein tried to form a generalized theory of gravitation that would unify the gravitational and electromagnetic forces (and perhaps others), guided by a belief in a single origin for the entire set of physical laws. These attempts initially concentrated on additional geometric notions such as vierbeins and "distant parallelism", but eventually centered around treating both the metric tensor and the affine connection as fundamental fields. (Because they are not independent, the metric-affine theory was somewhat complicated.) In general relativity, these fields are symmetric (in the matrix sense), but
Unified communications service provider, or UCaaS (UC as a Service). While both offer their respective advantages, all of these approaches can be grouped under the single umbrella term of "unified communications". Unified communications is sometimes confused with unified messaging, but it is distinct. Unified communications refers to both real-time and non-real-time delivery of communications based on the preferred method and location of the recipient; unified messaging culls messages from several sources (such as e-mail, voice mail and faxes), but holds those messages only for retrieval at a later time. Unified communications allows for an individual to check and retrieve an e-mail or