© David Kaplan.
The Higgs mechanism is described by a field filling all space that goes through something like a phase change and gives mass to itself and most particles of the Standard Model. The movie above is a (very) loose analogy. The lake represents the field, and a particle could be the ripples moving across the surface. If the lake freezes (changes from the liquid phase to the solid phase), the slow moving ripples no longer occur. The ice can instead vibrate. Thus, the character of the waves has completely changed when the material changes its phase. It is the "condensation" of the Higgs field that changed (in the early universe) the character of the fundamental particles we see.