Regular grammars are a type of formal grammar used in computer science and linguistics to describe regular languages. They consist of a set of production rules that define how strings can be generated. These rules can be categorized into two types: right-linear and left-linear, depending on the position of the non-terminal symbols in the production. Regular grammars are closely related to finite automata and regular expressions, which are tools for pattern matching and string processing. They are essential in designing compilers and interpreters, as they help in understanding the structure of programming languages and their syntax.