All digital images are divided into one of two core types, raster images (also know as ‘bitmaps’) and vector images. In a nutshell, raster images are composed of connected dots and vectors are images composed of connected lines.
This example shows the effects of vector graphics versus raster graphics.
- The original vector-based illustration is at the left.
- The upper-right image illustrates magnification of 7x as a vector image.
- The lower-right image illustrates the same magnification as a bitmap image.
Raster images are based on pixels – hence the loss of clarity when the image is scaled, while vector-based images can be scaled indefinitely without degrading.
So, now your asking the positives and negatives of both modes. And the situations where you would use vector or rastered graphics
Vector image formats advantages
- Resolution independent
- Smooth curves
- Small file sizes
Raster image formats advantages
- Only format that will show smooth gradients and subtle detail necessary in photographic images
- Allow for color correction much easier then vector images
Common uses for raster image formats
- Continuous tonal images like photographs
- Used on the web where there are no vector formats currently supported with out plugins
Common uses for vector image formats
- Logos which are generally a few solid colors and need to be shown at a variety of sizes
- Creating specialized text effects
- 3D and CAD programs
Both file formats are used incorrectly by many people. Lots of people use photoshop for doing work which would be much better suited for a drawing program. You can use the wrong file format but it is much more efficient to understand the differences between the two and use the correct one.
check out Design Battle: Vector vs. Raster for the full story