A context-free language (CFL) is a type of formal language that can be generated by a context-free grammar. In this grammar, rules are applied to replace a single non-terminal symbol with a string of non-terminal and terminal symbols. This allows for the creation of complex structures, such as nested parentheses or balanced expressions, which are common in programming languages and mathematical expressions. CFLs are recognized by pushdown automata, a type of computational model that uses a stack to keep track of information. They are more powerful than regular languages but less powerful than context-sensitive languages. Examples of context-free languages include programming languages like Java and Python, which rely on context-free grammars for their syntax.