IDE stands for ‘Integrated Development Environment‘.

IDE is the place where you write your code.

For most of beginning AS developers this is Flash IDE (Flash MX, Flash 8 or Flash CS3). For basic code like gotoAndStop and gotoAndPlay standard code editor is just nothing more needed.

However, when you grow up as a programmer and step deeper into ActionScript classes and language paradigms you will feel that Flash IDE is not what developers might dream about. There is a number of editors which support ActionScript language, however I would recommend the one I use myself.