Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Both GIMP and PS are aimed at raster image editing and are also capable to use vector drawn paths and shapes. In this post we will compare the two softwares, according to current standards.
1- Basic editing is the same for both the softwares: Photoshop and GIMP, both provide basic set of tools for image editing. Equivalent quality image editing can be accomplished in both the softwares. Also, if you are to create images for the web than both softwares will do a similar job.
2- Advanced Features, do you need them? Photoshop is loaded with excessive features as compared to GIMP. But here it must be noted that an average user does not require sophisticated editing capabilities and only handful of people use these advanced features.