Satisfiability Modulo Theories (SMT) is a decision problem that extends propositional logic by incorporating theories such as real numbers, integers, and arrays. It determines whether a logical formula can be satisfied by some interpretation that adheres to specific constraints defined by these theories. SMT solvers are tools that automate the process of checking satisfiability. They combine techniques from first-order logic and constraint satisfaction to efficiently handle complex formulas. This makes SMT useful in various fields, including formal verification, software testing, and automated reasoning.