After defining what graphic design is, and what is not, let’s tackle one of the most important things to know about graphics: the difference between raster and vector.
The most important thing to remember is that the distinction between vector and raster graphics is more technical than visual. In other words, it is more about the way graphics are made than it is about how they look like.
Now based on the comparison table above, let’s look closer at the difference between vectors and rasters. The most significant difference between the two is composition, or more correctly the type of data and the way is stored and interpreted by the device (check the chart below for reference).
On one hand, a raster image is a set of pixels stacked against each other with various colors and transparency values. In order to display a raster file, the device (computer, mobile…) determines the relative position, color and opacity of each and every pixel, then projects them with their respective values. On the other hand, a vector image is made up of path-based shapes and lines, stored as complicated mathematical formulas that only appropriate softwares can decipher. The computer draws all the points of a path, links them together then fills the result with the right color and opacity, and this goes for each and every path of the image.
The comparison above shows clearly why raster graphics are unscalable: zoomed in, the device has no other way to enlarge the output than to widen every pixel of the file, resulting in jaggy and pixelated graphic. Vector graphics can be expanded without any loss of quality since the computer has all the data that it might need to display the same graphic on a larger scale. This is the main reason why logos are always made using vector graphics: Be it a match box or a plane coating, it can fit anywhere with exactly the same amount of details.
While the previous graphic was in preview mode, the way we humans see the output, the graphic below is in outline mode: the way computers see the input!
As far as convertibility goes, vectors can become rasters very easily with pixel perfect fidelity, while rasters can be hard to vectorize, with often sub-par results. The reason behind this is the fact that vectors provide much more data about the composition of a graphic than do rasters: moving from raster to vector requires additional data that the computer is in most cases unable to guess perfectly.
So, if vector graphics are this awesome, why are we still using jpegs and pngs? Well, that’s because raster graphics are lightyears ahead of vector graphics in terms of displayability and portability: They can be displayed on almost any device without any software requirements! Vectors can only be viewed and edited with vector design applications like Adobe Illustrator or CorelDraw. (list here)
In a nutshell, raster graphics are more like “hey computer, put these pixels together!“, while vector graphics are more like “hey computer, here is what I want, now draw itt!“.
Credit: The pictograms in the chart are belong to bserv. Get them here.