Just to clarify further, aircraft are limited by RTOW (regulated take off weight).
This is defined as the LOWER of MTOW (Maximum Structural Take Off Weight,fixed figure) and PLTOW (Performance Limited Take Off Weight, variable with temp, density altitude, runway length, physical decrements to aircraft, big hills at runway end etc)
Generally, in large aircraft, operating from long runways, MTOW tends to be more limiting.
Best Wishes