Along the different artwork and designs you’ll find the choice to download a ‘vector’ or ‘png’ file of the particular design. If you don’t know which to choose or don’t know the difference between vector and png then this mini tutorial will help you out. If you’re in a hurry scroll down at the end.
Actually ‘vector vs png’ is a wrong comparison, it should be ‘vector vs bitmap’ or ‘eps/svg vs png/jpg’.
There are several vector file formats of which eps and svg are the most common and widely used, but you also have dwg, ai, dxf,… There are also several bitmap file formats such as bmp, jpg, png, gif,… each having different specifications and standardizations. Some of them use compression to shrink the file such as jpg and png, the latter using a lossless compression so no information is lost during compression.
Vector files store a bunch of numbers which represent lines, curves, solid fills, etc… to make the artwork. Lines or artwork in particular that is drawn by underlying numbers and mathematics has several advantages. You can zoom in, stretch, change individual lines,items and artwork without losing quality. If you print it on A4 or A0, the sharpness and quality will be the same.
Bitmap files give a way to store a binary image, that is, an image in which each pixel is black, white or a color. When using bitmaps the resolution, dpi, ppi, are important. Dpi = dots per inch, the higher the dpi the more detail and sharpness will be in your image. However stretching the image lowers the dpi and thus the detail and sharpness. All artwork found here is stored in 600dpi, so you can easely use it on medium to big sized paperwork. If you use it on your website it is advised to lower the dpi and resize the image.
Vector files can be viewed and manipulated using vector software. Inkscape is a freeware program which can open svg and eps files. Commercial programs als exist but are rather expensive. Most svg files can also be viewed in webbrowsers such as Firefox.
Bitmap files can be viewed and manipulated using a widely variety of software free and paid. Gimp is free and opensource, also fastimage is a good alternative to do minor manipulations. Most importantly bitmap images can be imported in most software programs, think of Word, Powerpoint, etc… also they can be used on websites and viewed by webbrowsers.
So to put it simpe:
Vector: eps/svg, no quality loss when scaling/manipulating, highly customizable, learning curve, program of use: Inkscape
Bitmap: jpg/png, easy to use in variety of software (word, powerpoint, website,…), quality loss when scaling/manipulating, no learning curve to use them, program of use: gimp, fastimage,…