Facility is a term used that refers to a set of data pertaining to a unique database residing within the WIMS database server.

A facility has a Facility Name and a Unique Identifier.  Example, the Tutorial - Rocky Creek WWTP database has a Unique Identifier of OPSWWTUTOR as shown in Facility Setup:

In MS SQL Server the Unique Identifier is the database name:

In Oracle, the Unique Identifier is the Schema Owner of the database objects for a facility.