Big-O notation in 2 mins or less:

→ Big O tells how much slower the code gets as the input increases.

→ There are best, average, and worst cases for a specific algorithm.

→ Plus, there are Big Os for time, memory & storage efficiency.

→ Big O helps to understand which data structures or algorithms have better performance.

→ Big O shows growth rate and not the actual speed, so it's crucial to test the input data.

What else would you add?