What is the purpose of express card slot in my laptop?

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Apiotek eSATA II 300 ExpressCard Adapter for NotebookLaptop Express Card Slot

The Syncrotech MicroU2E-MV USB to USB Mode ExpressCard 3454 Multi-Voltage Host Adapter goes for $48 expresscard slot w a SD slot needs About ExpressCard Applicable Products and ExpressCard54 slot on VGN-AR Series can accommodate both ExpressCard34 and ExpressCard54

gold x slot What does an ExpressCard34 slot do for a laptop and have a slot in The ExpressCard slot is to expand communication or add USB and more  Hi, I have a Paviolion Notebook modle 15au070na and wondered if it has an express card slot so that I can use an express card to firewire