Webster's Dictionary refers to it as: "A feeling of self-assurance arising from one's appreciation of one's own abilities or qualities."
On the first day of Steelers minicamp the definition of confidence was Devin Bush.
Just a few hours after having the playbook thrust into his hands, the team's first-round draft pick was out on the field calling the defense like it was second nature to him.
"You have to jump in your playbook and be confident," said Bush in a calm, matter of fact manner.
Now, before you think he has a photographic memory and got it down pat in just those few hours, think again. Yes, he went out there with the utmost confidence and handled it like a pro. But at the same time, he is new…and he is learning.
"I have quite a bit to learn," said Bush. "I have to learn how to speak the language of the defense, get comfortable with my plays. I know the concepts. I understand the defense we are running. I have to learn the language. It's just different things they call. Different languages they speak.
"Getting out there and being vocal, whether I was right or wrong and just trusting what I see."
You can see how the confidence just oozes from him, and in football it's a must.
"Confidence is very important," said Bush. "If you lack confidence in this league you are going to talk yourself out of a lot of things. You aren't going to be able to accomplish things. The confidence gives you the motivation to keep going through."
Bush spoke as he walked off the field at the UPMC Rooney Sports Complex following his first practice, a practice he was anxious for from the moment the Steelers traded up to select him in the first round.
"It was fun," said Bush. "Just being back out there in football mode, learning the plays and being around different guys. It's football again so I am happy to be back.
"Just the fact that you are playing for a big organization. You are around a lot of great talent, a lot of good people to learn from. You are just out here playing football."
Bush, who said he is happy wearing No. 55, welcomed the opportunity to put on his jersey and helmet for the first time today and finally get to work.
"It felt great. I am part of the Steelers organization," said Bush. "I am a Steeler.
"Now I just want to get familiar with the playbook, with the languages. Just get familiar with my play calling. I didn't feel out of whack. I knew there would be some hiccups. I am still learning.
"I want to show that I belong here. That I belong in the NFL and I am going to play here a long time."
And play for a long time with confidence.