Vector is a computer image file that uses paths with a start and end point. With a vector program such as Adobe Illustrator or Flash you can add or remove point or nodes to the path that will allow you to bend, twist, stretch, straighten the path into any object your heart desires. People often confuse Adobe Illustrator with Adobe Photoshop or don’t know the fundamental difference between the two programs.
The alternative to vector graphic files are raster or bitmap based graphic files. Photographs or jpgs/jpegs, gifs, bmps, tiffs, pngs and many other popular computer graphic files are raster/bitmap based images which use pixels to represent an image. Each pixel in a bitmap has a defined color value and most photographs contain thousands or millions of pixels which comprise the picture. Adobe Photoshop is a raster based software program that allows you to edit raster files such as photographs. Vector graphics tend to have less colors and can be scaled
One of the advantages of vector files is that they can be scaled to any size and not loose their image quality. This is because vector files use mathematical calculations of the above explained paths to resize the image. Here is a visual example.
Our logo looks the same opened in either Illustrator or Photoshop.
If you zoom in or scale the above vector file you will see no pixels or loss of image quality.
On the other hand, when you zoom in on the above bitmap version you will see pixels, blurring, aliasing and an obvious loss of quality.
When to use a vector file vs a raster/bitmap file?
Vector - Most professional graphic designers create logos (and other images with less colors) with a vector based program such as Adobe Illustrator or Flash. This is beneficial because the logo can then be scaled smaller to fit on a small business card or scaled indefinitely and put on a giant billboard or the side of a skyscraper, for that matter. Also, vector files are typically extremely small in file size compared to bitmap images which makes them very easy and quick to work with.
Bitmap - Photos usually contain millions of colors, therefore it is common practice to keep them as bitmap based images. The higher the DPI or Dots Per Inch the higher quality the image. A 300 dpi photograph uses 300 dots or pixels per inch to create the image and is considered print quality. A 72 dpi photograph uses…. you got it, 72 dots per inch and is better for use on a website. Make sense?
Exceptions - It is, of course, possible to create a logo in a raster based program such as Photoshop and people do it all the time, but you’ll never be able to enlarge the image without loss of quality. If you are going to use Photoshop to create a logo we recommend setting your resolution to 300 pixels/inch when you first create your new document. You may then use this file for print, web, etc.
More soon… but if you have questions about this page or something we haven’t covered, comment below and we’ll gladly answer your question/s.
Also visit Wikipedia for a more detailed explanation of vector graphics.