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 notation allows you to analyze algorithms in terms of overall efficiency and scaleability. It abstracts away constant order differences in efficiency which can vary from platform, language, OS to focus on the inherent efficiency of the algorithm and how it varies according to the size of the input.