Originally developed by the Personal Computer Memory Card International Association (PCMCIA), the ExpressCard standard is maintained by the USB Implementers Forum (USB-IF).

The major benefit of the ExpressCard over the PC card is more bandwidth, due to the ExpressCard's direct connection to the system bus over a PCI Express ×1 lane and USB 2.0, while CardBus cards only interface with PCI.

More recently, virtually all laptop equipment has 480 Mbit/s Hi-Speed USB 2.0 ports, and most types of peripheral which formerly used a PC Card connection are available for USB or are built-in, making the ExpressCard less necessary than the PC Card was in its day.

An ExpressCard slot was commonly included on high-end laptops from the mid 2000s to the early 2010s: Because of the lack of backward compatibility, some laptop manufacturers initially released models incorporating both CardBus (PCMCIA, PC Card) and ExpressCard slots.

[10][11][12][13][14][15][16][17][18][19][20][excessive citations] In November 2006, Belkin announced that it was launching the first ExpressCard docking station, which uses the PCIe part of an ExpressCard connection to enable 1600x1200 video and the USB part to provide USB, audio and network ports.

[21][22] This points to the ability for ExpressCard to allow more capable non-OEM docking stations for laptop computers.

Sony also uses the ExpressCard/34 form factor for the flash memory modules in its XDCAM EX/SxS based camcorders, making the copying of video data between these cameras and ExpressCard-equipped laptops easier.

For external desktop graphics card enclosures and other peripherals that interface with PCI Express, Thunderbolt has supplanted ExpressCard in that role due to its faster speed and ability to use multiple PCIe 2.0 lanes; the first and second Thunderbolt revisions offered 20 Gbit/s of maximum bandwidth with four PCIe 2.0 lanes while ExpressCard could only muster 5 Gbit/s maximum with one PCIe 2.0 lane.

[30][31] After the dissolution of the PCMCIA in 2010, the specification, associated documentation and licensing responsibilities were moved to the USB Implementers Forum.