COMSOL Multiphysics is a finite element analysis, solver and simulation software / FEA software package for various physics and engineering applications, especially coupled phenomena, or multiphysics.
In addition to conventional physics-based user interfaces, COMSOL Multiphysics also allows entering coupled systems of partial differential equations (PDEs). The PDEs can be entered directly or using the so-called weak form. Since version 5.0 (2014), COMSOL Multiphysics is also used for creating physics-based apps. These apps can be run with a regular COMSOL Multiphysics license but also with a COMSOL Server license. An early version (before 2005) of COMSOL Multiphysics was called FEMLAB.
For more details see Comsol .