An alternative way to reposition and resize controls is to use variable calculations. For instance we could write cmdBottomRight. This would have the effect of always centralising a control. The good thing about using graphics today is that you don't need to be an artist to make a good interface, all you need to know is what you should put into an interface to make it good. Many Windows applications come with a large amount of clip-art which is copyright free and may be used in documents, charts, presentations, etc.
Bitmaps store data about every single pixel in the image.
The larger the image, and the higher the colour resolution, the bigger the resulting file size is. However, this format is not very efficient and results in large file sizes. JPG images can have several different levels of compression, but note that the higher the compresssion used the poorer the image will look. Icons are similar but normally much smaller physically in size. They can be used for application icons displayed on the desktop or used for toolbars within applications.