Pixel wise 2560x1440 is just under half of 3840x2160 so I think it makes some sense for shorthand purposes.
Really the actual names are more precise. HD, FHD, QHD, UHD, WQHD, and so on.
Though in the this case, 2560x1080 would still be a little much for a 1050Ti, would probably recommend a GTX1060 or RX580 for that.