There are a great number of resources available to the pilot. Using these resources brings information to the pilot, allowing for better awareness.
Internal Resources
An internal resource is something located inside the airplane. Checklists, aeronautical and performance charts, placards, and instrument markings are all internal resources available for the pilot. Equipment such as an autopilot, GPS or radio navigation system, a flight computer, or the clock are also important resources. Passengers or other pilots inside the airplane can also be used as a resource.
External Resources
An external resource is something outside the airplane. The radio gives access to air traffic control, who can provide traffic advisories, weather information, and assistance in an emergency. At smaller airports, the radio is used by pilots who broadcast their location and intentions to each other. Additionally, someone on the ground at a small airport can often be contacted by radio for current weather and airport information.
This is only a few of the resources available. The important thing is to realize that everything, checklists, procedures, etc., are provided to the pilot as a resource. There are pilots who choose not to use many or most of these resources. However, using resources provides better awareness, and awareness is the key to making good decisions.