Properties of a Binomial Experiment
Key Questions

In a Binomial setting, there are only two possible outcomes per try. Depending on what you want, you call one of the possibilities Fail and the other one Succes.
Example :
You may call rolling a 6 with a die Succes, and a non6 a Fail. Depending on the conditions of the game, rolling a 6 may cost you money, and you may want to reverse the terms.In short:
There are only two possible outcomes per try, and you may name them as you want: WhiteBlack, HeadsTails, whatever.
Usually the one you use as#P# in calculations is called (probability of) Succes. 
In a BInomial setting there are two possible outcomes per event.
The important conditions for using a binomial setting in the first place are:
 There are only two possibilities, which we will call Good or Fail
 The probability of the ratio between Good and Fail doesn't change during the tries
 In other words: the outcome of one try does not
influence the next
Example :
You roll dice (one at a time) and you want to know what the chances are that you roll at lest 1 six in 3 tries.
This is a typical example of binomial: There are only two possibilities:
6 (chance#=1/6# ) or not6 (chance#=5/6# )  The die has no memory, so:
 Every next roll has still the same probabilities.
You can set up a chancetree, but you can also calculate the chance of three Fails, which is
#5/6*5/6*5/6=125/216# And your chance of succeeding would be
#1125/216=91/216#