It's the standard downstream port on a printer, hub, or industrial controller — the square-ish one that accepts the flat Type-B plug from a peripheral cable. The board lock holds it down during wave solder and resists the shear from repeated cable yanks.
Why 1500 Mating Cycles Matters for Field Use
Standard USB-B receptacles are often rated for 500 to 1500 cycles. The 5787834-1 lands at 1500, which is the high end for this form factor. The gold or gold-palladium contact finish resists fretting corrosion over those cycles; a tin-plated contact would wear through and oxidise long before 1500 mates. On site, if you're swapping a failed port, this one will outlast the equipment's service life in most cases.
Board Lock and Through-Hole Termination
Without it, the solder joints on the four signal pins would take the mechanical load and crack over time. The through-hole termination gives a stronger mechanical bond than an SMT version — important for a connector that sees frequent plugging. The vertical mounting means the cable enters perpendicular to the board; if your enclosure has the port on the same plane as the PCB, this is the orientation you need.