Efficiency
Amount of resources used by an algorithm, which can affect how long it runs
Time complexity of an algorithm
How fast the algorithm runs
Space complexity of an algorithm
How much memory the algorithm needs
Worst case complexity
When we happen to choose an input that requires the longest time or greatest workload
Best case complexity
When we choose an input that requires the shortest time or smallest workload
Average case complexity
Calculated by averaging the times for every possible input