In 80286, segment tables are introduced. They are Local Descriptor Table, or LDT (allocated to each process) and Global Descriptor Table, or GDT (set up and mainly used by the operating system). A segment register contains a 13-bit pointer to an entry the descriptor table. Each entry in the descriptor table ( descriptor) contains 24-bit base address for the segment (Total address space is 16MB). However the displacement with a segment is still limited to 16-bit. Since LDT is allocated to each process, it is possible to share a segment with multiple processes by having descriptors to point to the same physical memory address.