A weighted sum of individual loads (DL, LL, WL, EL) used in a single design check. Code-specific factors.
IS 456 typical: 1.5(DL+LL), 1.2(DL+LL+WL), 0.9DL+1.5WL. ACI uses 1.4D, 1.2D+1.6L, 1.2D+1.0W+L+0.5(Lr or S or R).