The 2842144-5: That pitch sets the board footprint — each pair of contacts sits 2.00 mm apart, so the total width across the two rows is 2.00 mm, and the length across 10 positions is 9.00 mm from center of pin 1 to center of pin 10. This makes it easier to probe or hand-wire, but the pins are exposed and more vulnerable to bending during handling or mating.
Surface mount termination and pick-and-place readiness
This is a surface mount header with solder termination — no through-hole leads. The flat SMT feet sit on the PCB pads and reflow with the rest of the board. The insulation height is only 0.059 inches (1.50 mm) above the board surface, so the mated stack height stays low — useful when the board-to-board gap is tight.