Your computer is constantly recording everything that it does and stores them in log files. These log files become very useful when troubleshooting, because you can use them to help identify programs or processes that may be causing your computer to act weird or be slow.
A utility called Console comes with every Mac and is a quick way to view your log and crash files. I go over how to use console, how to use log files, and what to look for in console when troubleshooting on a Mac.
This video is part of a Troubleshooting Guide for Mac, where I cover some of the best tools available on your Mac to help identify any problem.
