extended partition
In the context of Boot Manager, a fixed disk partition which contains one or more logical drives, and on which certain operating systems such as OS/2 Version 2.0 may be installed. An extended partition and its logical drives are visible to the operating system at all times, regardless of which primary partition is currently active. Hence extended partitions are useful for the storage of programs and data which must be shared between multiple operating systems in an OS/2 Version 2.0 Boot Manager environment.