Logical partitions are those partitions contained within an extended partition. In terms of use they are no different than a non-extended primary partition. The number of logical drives that may be created in extended partition is limited by the number of available drive letters and the amount of hard drive space available for creating drives.

A partition on a hard drive which is capable of containing data and being recognized by an Operating System.

a partition inside the extended partition

The ESA/390 term for a set of functions that create the programming environment that is defined by the ESA/390 architecture. ESA/390 architecture uses this term when more than one LPAR is established on a processor. An LPAR is conceptually similar to a virtual machine environment except that the LPAR is a function of the processor. Also, the LPAR does not depend on an operating system to create the virtual machine environment.

The division of a computer's processors, 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 applications.

A logically distinct portion of memory or a storage device that functions as though it were a physically separate unit.