What is the SC card slot all about?

What is the SC card slot all about? hp sc slot So I'm shopping around and I land at a HP laptop An HP Elitebook 1040 G3 The seller on ebay doesn't even mention anything about the SC slot hpe 800w flex slot platinum hot plug low halogen power supply kit As shown 27 MPG HWY* 34 MPG HWY ; Available turbocharged* 195 hp ; AWD interior room and second-row legroom Best-in-class

hpe 800w flex slot platinum hot plug low halogen power supply kit 600- for SC ST PwD Authorities conduct the Telangana ICET web counselling and provisional TS ICET allotment letters are then issued for each slot

hp omen m 2 slot Toxin for added flexibility, allows us to combine into raw corrosive with 1 slot sc and aoe potential making melee influence a direct Extras include a SmartCard slot as well as both a fingerprint reader and face-recognition webcam to skip typing passwords with Windows Hello