In the realm of quantum information, cavity QED is the most effective scheme that can realize the quantum information process. In cavity QED, the core is the interaction between atoms and cavity modes. Based on the frequencies of atomic transitions and cavity modes, we can divide the interaction into two different kinds, one is the resonant interaction where the atomic transition frequency is equal to cavity mode frequency, the other is the large-detuned interaction where the atomic transition frequency is large detuned from the cavity mode frequency. From the two different kinds of interaction we all can prepare entangled states, teleport unknown states and realize the quantum logic gates. By comparison, we conclude that the large-detuned interaction scheme would become a promising scheme, and would make the realization of quantum network and quantum computer possible in the near future.