Example Concept: BEM (Block Element Modifier) is a methodology that helps create reusable components and code sharing in front-end development. It uses a naming convention that makes the relationships between styles clear. For example, a block is a standalone entity like "button", an element is a part of a block like "button__icon", and a modifier is a variation of a block or element like "button--large". CSS Modules scope styles locally by default, preventing global conflicts, and are often used in React projects. Scoped styles in frameworks like Vue.js allow styles to be applied only to the component they are defined in, avoiding conflicts with other components.