It's a board-to-board interconnect on the standard 0.100" (2.54mm) pitch, through-hole solder termination, with tin plating on both the mating and post sides. Rated 5A per contact at 110V, the UL94 V-0 housing suits equipment inside an enclosure requiring flame rating.
The 0.100" pitch is the de facto 2.54mm grid — footprint compatibility is the first check against the PCB layout. The 5A rating is typical for this class of unshrouded header, adequate for signal-level and low-power duty; the tin mating finish (100.0µin) is standard for low-cycle, cost-sensitive applications, not for repeated reconnection.