Matheuristics[1][2] are problem agnostic optimization algorithms that make use of mathematical programming (MP) techniques in order to obtain heuristic solutions.
Problem-dependent elements are included only within the lower-level mathematic programming, local search or constructive components.
An essential feature is the exploitation in some part of the algorithms of features derived from the mathematical model of the problems of interest, thus the definition "model-based heuristics" appearing in the title of some events of the conference series dedicated to matheuristics matheuristics web page.
A word of caution is needed before delving into the subject, because obviously the use of MP for solving optimization problems, albeit in a heuristic way, is much older and much more widespread than matheuristics.
Some approaches using MP combined with metaheuristics have begun to appear regularly in the matheuristics literature.