In Doodle, an effect such as Renderer carries out the instructions in a Picture. In the case of Renderer, this is drawing the picture on the screen. Converting a Picture to another type or saving it to a file are another very common effects managed by Writers, for example, a Base64Writer or a FileWriter.

You will mostly interact with effects by convenient syntax. For example, when you call draw on a Picture you are using an effect via such a convenience.

Creating Pictures→