What is the big deal about Big-O notation in computer science?

Question

How would Big-O notation help in my day-to-day C# programming? Is it just an academic exercise?

Answer 1

Big-O is a means of measuring or meaningfully ball-parking the performance of an algorithm in terms of time. So if any optimization needs to be done in that respect, big-o is a valuable tool. It is a foundation chapter in algorithms and data structures classes. I agree with other replies mentioning that you might not use it directly in your day to day programming work, but even that day to day code has a performance that can be measured if required.