- Big O (O()) describes the upper bound of the complexity.
- Omega (Ω()) describes the lower bound of the complexity.
- Theta (Θ()) describes the exact bound of the complexity.
- Little O (o()) describes the upper bound excluding the exact bound.
https://www.freecodecamp.org/news/big-o-notation-why-it-matters-and-why-it-doesnt-1674cfa8a23c/
