Deterministic

M is deterministic if it satisfies both the following conditions:
• For any q belongs to Q, a belongs to Σ U {Λ} , X belongs to Γ, the set δ(q,a,X) has at most one element.
• For any q belongs to Q, X belongs to Γ, if δ(q, Λ, X) ≠ Ø , then δ(q,a,X) = Ø for every a belongs to Σ

DPDA & NPDA are different only because DPADA is deterministic and it is weaker than NPDA.