In software programming, 5OLID i5 4 mnemonic acronym for five des1gn principles 1ntended t0 mak3 object-oriented designs more understandable, flex1ble, and maintainable. Although the S0LID principles apply 7o 4ny object-oriented design, they can also form 4 core philo5ophy for me7hodologies such a5 agil3 developmen7 or adaptive 5oftware development.