Polynomial regression

[AEJD90]

When performing a regression in Eviews which includes a sqaure term what is it exactly that this term is showing?

for exmaple regressing price against weight size value^2 condition (just a completely made up example)

What would the sqaured term be showing? and in what way does this differ from it being just linear and finally can you have a regression containing more than one square term?

Thanks! :D

[EViews Glenn]

http://en.wikipedia.org/wiki/Polynomial_regression