Asymptotic notation

Asymptotic notation is a way of expressing how something changes as it gets bigger or smaller. For example, if we want to measure how long it takes for a program to run, we might measure how the time it takes increases as the size of the program increases. Asymptotic notation is a way of writing how this change happens, using symbols to represent different kinds of changes. For example, O(n) means that for a program of size n, the time it takes to run increases linearly, or "in a straight line"; O(n^2) means that for a program of size n, the time it takes to run increases by the square, or "in a curve".