**Common Data** is shared data within the [[Foundation (CSDM domain)|Foundation domain]] of the [[Common Service Data Model|Common Service Data Model]] (CSDM), a reference architecture developed by [[ServiceNow|ServiceNow]] that provides prescriptive guidance on service-related definitions and data modeling within the ServiceNow AI Platform. Common Data represents referential information that is prevalent throughout the ServiceNow AI Platform, with multiple products depending on this data to provide business value. Common Data encompasses several out-of-box tables that support organizational structure and core reference data: [[Company (CSDM)|Company]] (core_company) for legal entities both internal and external; [[Business Unit (CSDM)|Business Unit]] (business_unit) for organizational hierarchy within companies; [[Department (CSDM)|Department]] (cmn_department) for further stratification of business units; [[Location (CSDM)|Location]] (cmn_location) for geographical positions with hierarchical support; [[Group (CSDM)|Group]] (sys_user_group) for sets of users sharing common purposes; [[User (CSDM)|User]] (sys_user) for individuals with access to the ServiceNow instance; and Building (cmn_building) for physical structures. Common Data elements are not [[Configuration item|configuration items]] but serve as critical referential data. When planning Common Data, organizations should consider whether they have a trusted source for the data, how often it changes, whether data depth meets CI requirements, and who will maintain the data. ServiceNow recommends establishing Common Data as part of the Foundation stage of [[CSDM Adoption Stages|CSDM adoption]] to avoid costly rework across the [[CSDM Service Life Cycle|CSDM Service Life Cycle]].