Photoshop and Illustrator are two very different programs by Adobe. Non-designers can wonder what the differences are. Photoshop can seem more well known, because of its use on photographs of models in magazines. Illustrator is the equally important, possibly less debated, program with very different purposes.
The purpose of the Photoshop application is implied by its name. Adobe lists a couple of benefits on the web site, “Create beautiful 2D compositions that feature 3D models. Easily reposition models and adjust camera angles and lighting.” Image moving and retouching are also featured as key benefits, “Combine multiple images, remove objects and retouch photos using a complete set of professional photography tools.” Photoshop is all about changing photographs, and creating lifelike 3D images.
Pixels are used in Photoshop files. Adobe describes pixels as ‘building blocks of images.’ When zooming in very close in a PSD, tiny squares can be seen. A photo’s pixel density is typically labelled as pixels-per-inch (PPI), not to be confused with dot-per-inch (DPI). The very thing a PSD is made of, is very different to that of an Illustrator AI.
Adobe Illustrator is for drawing pictures. It is also great for quickly putting together layouts. Although InDesign is a big program for layouts, Illustrator is handy for memes and web banners. 3D and perspective drawings can aim towards realism with graphs and grids. Illustrator Draw is also available for iPads. These purposes of drawing are very different to the pixel editing of Photoshop.
Illustrator uses vectors. These are mathematical lines for telling the computer the direction a shape will go in. Designers can stretch shapes, either in proportion or not, and the computer knows a clear line needs to go in a particular degree of movement. The result is greater clarity. The difference is that Photoshop can only stretch pixels away from each other, which can look blurry.
Vectors are sometimes an unfamiliar concept for people to understand. The main thing to know is that a vector keeps its clarity, whereas pixels can look blurry when they are spread out. Pixels are normal when working on photographs. Vectors are a way to get clear illustrations. Neither is better or worse. They are different in their own rights, with very different purposes.