Factors and zero's are not the same but they do come from the same place. Zero's are where the graph crosses the x-axis and factors are what you factor out of the equation of the graph. Factors will become zero's when you change the sign. The factors (x-4)(x+2) would in fact, be zero's at 4, -2. The degree of the polynomial helps us predict the number of zero's because that is how many zero's there should be on the graph. If a polynomial has a degree of 4, there should be 4 zero's on the graph. It does not always tell us the number of factors though, there are many more factors that can be found than zero's necessarily.