Adobe Illustrator is a vector graphics editor developed and marketed by Adobe Systems.  Vector graphics is a technology that allows objects to be infinitely scalable to either very large or very tiny sizes without degradation in quality.  Often when an image is expanded to a large size the image distorts with rough squares and sharp edges, known as pixels.  This is a raster image which is based with a particular size in mind.  Vector images are based on geometry and relative location and angles, so its proportions can be scaled in any direction without pixelation or distortion.  Illustrator also includes 3-dimensional capabilities allowing users to extrude or revolve shapes to create simple 3D objects.

Adobe Photoshop is a raster graphics editor developed and published by Adobe Systems for Windows and OS X.

Photoshop has become the de facto industry standard in raster graphics editing, such that the terms “photoshopping” and “photoshop contest” were born. It can edit and compose raster images in multiple layers and supports masks, alpha compositing and several color models including RGB, CMYK, Lab color space (with capital L), spot color and duotone. Photoshop has vast support for graphic file formats but also uses its own PSD and PSB file formats which support all the aforementioned features. In addition to raster graphics, it has limited abilities to edit or render text, vector graphics (especially through clipping path), 3D graphics and video. Photoshop’s featureset can be expanded by Photoshop plug-ins, programs developed and distributed independently of Photoshop that can run inside it and offer new or enhanced features.