Database Concept. An
identifier for a single collection of data (e.g. a record, a row,
an object, etc.). The key for a
customer might be a customer number. The key for 800 number
information might be the 800 number plus the state code plus an
effective date, etc. One collection of data may have a "foreign key" that points to another collection of related data
in another file, table, database, collection of objects, etc.
Key System
An office telephone system that provides all users with
immediate access to outside lines when they press one or two
dedicated keys without needing operator's services. For example, a
six-button key system could have a hold button, four outside lines
and an intercom. Key systems typically have fewer lines and
telephones than a PBX system. A key
system can also be used with a
PBX or Centrex
system.
