A deterministic pushdown automaton (DPA) is a theoretical model of computation that extends the capabilities of a finite automaton by adding a stack. This stack allows the DPA to store an unbounded amount of information, enabling it to recognize a broader class of languages, specifically context-free languages. In a DPA, for each input symbol and stack symbol, there is at most one action that can be taken, making it deterministic. This means that the next state of the automaton is uniquely determined by the current state, the input symbol being read, and the top symbol of the stack.