the difference between 'annotation' and 'line'

do you ever tried to make annotations for a plot within a script? if you just draw a line using the gui and then take a look at the generated m-code (generate m-code), you'll find the code generator uses the function annotation. for me, this is not the best choice.
annotation uses a special layer (Annotation Layer). The coordinates are from 0 to 1 for x and y and covers the whole area of the figure.

Using the command 'line' (if you are trying to draw a line. there are others like text, and rectangle) it is posible to draw a line within the plot area, using x and y as data coordinates.

bye