Normal distribution curve determines the skewness of the data as to what extent is is disoriented from the normal distribution curve. Also, it is the probability distribution curve that determines whether the data set is two legged, one legged or it lies under which probability curve.
A basic algebraic linear equation is just a fancy way of saying "equation of a line". They are most likely referring to the formula y=mx+b, where m is the slope and b in the y intercept. :)
