Is there a specific key that the upright string bass plays in?

You could say that the bass reads in C, but an octave below the real bass clef. When you play an E, you hear a concert E. To be technical, or just using the correct terminology, the bass is in concert pitch. But about the octave lower, the C that we read is actually below on a ledger line in the real world.
All that was probably more wordy that neccicary.

gud day, im very particular to the bass key. just because its very complicated to me to analyze the key in a certain music. hope you can teach me as well as.. honestly im a begginer in playing a bass, and hopefully if possibly i can learn from you, especially in the bass key... jesse