Hey Guyz, can you anyone please explain everthing about insulin e.g

1. what is it
2. what do you mean when your insulin spikes, or making an insulin spike
3. what happens when it spikes
4. what are the disadvantages when it spikes
5. so no chocolate during the day no sugars at all cuase insulin to spike!!
6. why sugars after workout,what are te bennefits

Hope you help me out here cause everyone talks about it and i am not clear on this
Thanx JAY