While most of you have accurately described what SA is, the missing piece is what you do with that SA. The core skill for the pilot is positive decision making to avoid or extract themselves from a negative outcome. Positive decision making is the output from good SA. The difference between good and bad SA is whether you simply recieve the information, or whether you process and act pro-actively on that information. New pilots tend to fall back on a (falsely) percieved level of ability to avoid a negative outcome whereas experienced pilots take longer to make (good) decisions based on processing the available SA details.