When drawing in Flash, you will be creating vector graphics as opposed to raster graphics (also known as bitmaps). Vector graphics use math to refigure curves, lines and fills based on the size of the graphic. That means if you zoom in, or resize, it will not lose quality.
If you zoom in on a raster graphic (like a photo saved as a .jpg) it will not look good. You will see all of the square pixels. Raster graphics do not adjust if you change the size of the image.
Many of the Drawing Tools in Flash are very similar to tools popularized in other graphics programs such as Adobe Photoshop or Adobe Illustrator. However, there are key differences that you will learn.