Functional programming is a programming paradigm focused on using functions to create software, emphasizing immutability and statelessness. It contrasts with object-oriented programming (OOP), which centers on the use of objects and classes to encapsulate state and behavior. While functional programming prioritizes first-class functions and higher-order functions, OOP relies on inheritance and polymorphism. This distinction influences how developers approach problem-solving, with functional programming typically leading to more predictable and maintainable code, particularly in concurrent and parallel processing scenarios.