the module you import is pygameand inside the pygame module are the font and surface modules inside those modules are the font and surface data types the pygame programmers made the modules begin with lowercase letterand the data types begin with an uppercase letter this makes it easier to distinguish the data types and the modules constructor functions create pygame rect object by calling function named pygame rect(the pygame rect(function has the same name as the pygame rect data type functions that have the same name as their data type and create objects or values of this data type are called constructor functions the fill(method for surface objects draw the white background onto the surface windowsurface fill(whiteyou want to fill the entire surface stored in windowsurface with the color white the fill(function will completely cover the entire surface with the color you pass as the parameter (in this casethe white variable is set to the value ( an important thing to know about pygame is that the window on the screen won' change when you call the fill(method or any of the other drawing functions these will change the surface objectbut the surface object won' be drawn on the screen until the pygame display update(function is called this is because modifying the surface object in the computer' memory is much faster than modifying the image on the screen it is much more efficient to draw onto the screen once after all of the drawing functions have drawn to the surface pygame' drawing functions the pygame draw polygon(function draw green polygon onto the surface pygame draw polygon(windowsurfacegreen(( )( )( )( )( )) polygon is multisided shape with straight line sides circles and ellipses are not polygons figure - has some examples of polygons