HELP! SES Light

[Supermanguy81]

Alright, I'm going to do some research on this website, however, to cover all bases I'd ask the following:

What does "Service your Engine Soon" mean? Is this bad? Is it expensive?? I got it today while driving to the gym (pumped my workout more-frustrated) and didn't know what it meant.

Some background....my car recently had the "yellow oil lamp" on, which indicates that it needs about (1 quart) of oil, at least my understanding from reading the blogs on this awesome website! I did check the level prior to putting oil in. We'll the oil I bought was Castrol "Full Synthetic" 5w-30. All of this happened yesterday, and I'm curious of any of this (adding oil) could have caused the SES light to come on?