Confidence, to me, is loving yourself to the point where you know your worth but you also know when you need to better yourself--in the right ways. It's knowing how awesome you are but not being arrogant and conceited. It's being humble.
It's loving and accepting every inch of your body, while also keeping it and yourself healthy; even if that may require some work.
It's the ability to reject hatred and negativity from the mouths of others directed towards you, while also being able to understand and listen when you are in the wrong.
It's laughing and smiling on days when it seems like you never could again, while also allowing yourself to feel and cry and be upset when you should be. Feeling your emotions while they happen and allowing yourself to feel everything will make you a stronger, happier person. It will give you the ability to move on faster--it's as simple as that. Things, especially feelings, cannot be ignored forever.
It's being selfless and sometimes putting others' feelings and concerns above yours--caring for others, while also being a little selfish with yourself sometimes. We have to take care of ourselves in order to possess the capability to take care of other people.
It's being respectful towards others and biting your tongue in situations where all you want is to spew hatred right back, while also taking up for yourself when needed and not letting people walk all over you. Confidence and strength go hand-in-hand. Strength can be shutting hateful people down and not letting someone walk on you like a dirty rug, but real strength is the ability to bite your tongue and to respond with only kindness and positivity when it's hard and it's the absolute last thing you want to do. You can't fight fire with fire.
It's using your insecurities as reasons to love yourself even more. No one is perfect. Every single person is different and each and every one of us are special. You are special. We all have things we may not like about ourselves, which is okay as long as you don't let these insecurities hold you back or stop you from doing things that you love.