Vector – created in adobe illustrator. these graphics are best used for logos and prints. Vector graphics can be made bigger without sacrificing image quality. as a result, you can increase the size of the picture and it will not be distorted.
Raster – created in adobe photoshop. These are the most common types of graphics. The main problem is that you cannot make the image bigger because the pixels become distorted as photoshop will ‘make up’ parts of the image. you can shrink the image but not make it bigger without sacrificing quality.
Overall – It depends what your purpose is. If you are making a logo, such as a tshirt design, I would go with illustrator. Most often though, people tend to work with photoshop as they are more familiar with it and its the industry standard photo editor.