What is the orbit theory?

Excuse me, but could you please elaborate on the concept of orbit theory? I'm not entirely familiar with it and would appreciate a clear and concise explanation. Specifically, I'm curious about how it applies to astronomy and how it helps us understand the movements of celestial bodies within our solar system. Additionally, I'm also wondering if there are any implications of this theory in other fields, such as finance or cryptocurrency, that might be worth exploring. Thank you in advance for your insights.