> How does back propagation work ?

How does back propagation work ?

Posted at: 2014-12-18 
I have read several documents on back propagation neural network,

the time series or recursion based, the weights and bias.. the inputs outputs targets,

but i am not able to grasp the subject practically.

for example : i have a data collected everyday for 3 years, i presume now i should be able to predict the value for the next year.

i have also tried to keep my understanding simple.. use 1 input (in my case temperature) 365*3 values.

but i am not understanding several factors.

my input will be just 1 yr values = 365.. or 3 yr values 365*3

what will be my target ?

what equation/formula should i use to calculate the hidden layer values ?