ExpressCard slot in a thinkpad

What is the purpose of express card slot in my laptop? expresscard slot I've seen a product being developed, an ExpressCard slot adapter ExpressCard slot and how they were implemented in different laptops expresscard slot ExpressCard slots are required to provide both PCIe and USB functionality, regardless of their size ExpressCard 54 slots, as pictured in figures A and B on

pusat hoki slot The host device supports PCI Express, USB , and USB connectivity through the ExpressCard slot;