Rebirth: it refers to the emergence of something that was forgotten or not used anymore. It's important to say that it does not appear the same way it was used before, new adaptations and modifications are done in order to create something that is new. The basic concepts or notions that give that thing it's identity are reused to inspire new ideas. An example would be the Reinassance in which the ideas of Ancient Greece were rebirth and inspired a huge artistic and cultural movement.
Classical: this concept refers to things that synthesize their context or the ideas that inspired them in such an effective way, they are able to give useful information and to inspire us no matter it's antiquity. That is the reason we always go back to them as they don't lose their value. They transmit information in a simple but powerful way, therefore they serve to inspire a lot of different ideas or points of viewing things. Imagine a movie that is cataloged as a classic. It doesn't matter if it is fifty years old, as you watch it you can see that it transmited things in an unique and new way, that helped develop that type of art. Modern filmmakers still use it to learn.
