ListLinePlot

ListLinePlot[{y_1y_2, ...}]
plots a line through a list of y-values, assuming integer x-values 1, 2, 3, ...
ListLinePlot[{{x_1y_1}, {x_2y_2}, ...}]
plots a line through a list of x,y pairs.
ListLinePlot[{list_1list_2, ...}]
plots several lines.