Vector and Raster Images, What's the Difference?

Graphics are broadly of two types: vector and bitmap, also known as raster.  There are differences in the properties and applications in these two types of graphics.  Here is a short primer about vector and raster graphics:

1.  Vector images are smaller in file size relative to bitmap graphics.  Here is why: Only the mathematical equations to render the image on screen are stored in a vector file.  Hence the compactness in the file size of vector graphics.  On the other hand, a bitmap image contains data about the location of and the color in individual pixels, resulting in a larger file size.

A pixel is a tiny square on your monitor screen.  By the way, the word pixel is the abbreviation for picture elements.  To understand bitmap images, compare your screen to a graph paper.  Say you want to draw a rectangle on it.  You will choose a location and fill a block of squares, with one or more colors, to create the rectangle.

2. Vector drawing programs are also known as object-oriented software, because it stores each element of the vector image like lines, shape, text, and other as an object.   Bitmap graphics software or image editing software is pixel-based.  It means you can do pixel-level editing of a bitmap image.

3. You can scale a vector image to any size without the loss in quality.  In case of a raster image, when you enlarge the size that differs much from the original dimensions, you will notice the image becomes jaggy.

4. Vector drawing software helps you create scalable, small file-size drawings.  Image editing software lets you edit photos, create continuous tones, develop artistic brush designs, and others.  CorelDraw and Adobe Illustrator are examples of vector drawing programs.  PaintShop Pro and Adobe Photoshop are some of the image editing software.

5. Some of the vector image file formats are EPS, AI, and SVG.  The file format for raster images include JPG (or JPEG), TIFF, BMP, WMF, and PICT.