Context-Sensitive Languages (CSLs) are a class of formal languages that can be defined by a set of rules where the production of symbols depends on the surrounding symbols. This means that the context in which a symbol appears can affect how it is replaced or transformed. CSLs are more powerful than Context-Free Languages (CFLs) but less powerful than Recursively Enumerable Languages. CSLs are typically recognized by Linear Bounded Automata, which are a type of computational model that operates within a limited amount of memory. These languages are useful in various fields, including computational linguistics and programming language design, where the structure and context of expressions are important for understanding and processing information.