How does grid search differ from random search? When is random faster?

Grid Search is a hyperparameter tuning method where all possible combinations of predefined parameter values are tested. Random Search, on the other hand, randomly selects combinations of parameters from specified ranges or lists.

Random Search can be faster when the hyperparameter space is large and not all parameters are equally important. In such cases, random selection allows for quicker identification of good combinations without spending time on testing all options, many of which may be inefficient.

Example: if you have 5 parameters with 10 values each, Grid Search will check 10^5 = 100,000 combinations, while Random Search might limit itself to, for example, 1,000 random attempts, which is significantly faster.