Explain what is meant by the execution time of an algorithm in the context of evaluating its efficiency.

The running time of an algorithm is the amount of time it takes for the algorithm to process input data and produce a result. In the context of algorithm efficiency evaluation, the running time is usually expressed as a function of the input size (e.g., O(n), O(n²)) and helps to understand how quickly the algorithm operates as the data volume increases. This is important for choosing the optimal solution, especially in resource-constrained applications like iOS.