Part of the Hardware glossary: A logical partition (LPAR) is the division of a computer's processor s, memory, and storage into multiple sets of resources so that each set of resources can be operated independently with its own operating system instance and application s.ach partition can communicate with the other partitions as if the other partition is in a separate machine. Logical partitioning was first studied by IBM in 1976 and later introduced by Amdahl and then IBM. Hitachi and Sun Microsystems also use forms of logical partitioning.