Console

OS X records a wealth of diagnostic information about virtually every application on the system, from routine status messages to detailed errors and warnings.

The Console utility allows you to monitor all these logs from a central location, which is essential when you are trying to track down a problem, or just want to learn more about what goes on behind the scenes. You can quickly search through thousands of messages and email logs, and delete the logs you no longer need. Console can automatically alert you when a specific system message occurs.