Title Bar - Displays the name of your file and the program name.
Menu Bar - Holds every tool, window, and preference available.
Toolbars - Displays tool icons. You can add more buttons or take them away. Also, you can hover your mouse over a tool to display it's name as a tool-tip.
Drawing Area - Where all the drawing magic happens. You will select a tool and then use it here.
Status Bar - This will update based on the tool you are using and tell you what action you can take next.
Measurement Bar - Displays dimensions based on what you are currently doing. You can also enter info here with your keyboard like how long you want a line to be or how many copies to make.