Chomsky Hierarchy is the 4 tier hiearchy of Formal Grammars, created by linguist Noam Chompsky.
| Grammar Type | Recognizing Automaton |
|---|---|
| Recursively Enumerable Grammar | Turing Machine |
| Context-Sensitive Grammar | Linear Bounded Turing Machine |
| Context-Free Grammar | Pushdown Automaton |
| Regular Grammar | Finite State Automaton |
| Context-Free Grammar is the most common. |