Photoshop is indisputably the longstanding leader when it comes to high-quality, professional-grade photo editing.

While there have been some worthy competitors, it remains the software that serious and professional photographers turn to for editing. A free editing software available is Gimp, so we thought we would do a brief side-by-side comparison.

The Basics:

Photoshop

Does frequent updates
Has more advanced tools than Gimp
Non-destructive adjustment layers
Cost includes Lightroom and cloud storage

Gimp

Free
Customisable
Includes various basic and mid-level editing capabilities
Good basic program

GIMP is an open-source program and free for download for GNU/Linux, OS X, Windows, and more operating systems. While it certainly comes close to Photoshop, but it's definitely not the same and doesn't offer a few key features you get with Photoshop.

GIMP (GNU Image Manipulation Program) has some of the same tools as Photoshop. It offers Layer editing, so it goes above basic cropping and color edits. There are also various advanced edits, like blemish correction, object removal, and local adjustment.

These advanced edit capabilities are what make it a close competitor to Photoshop. But we don't see it as an equal - at all. For professional, high-quality edits, you get what you pay for.

Here are a few differences:

Photoshop has four healing brushes. GIMP has just one brush.
Photoshop has the handy and time-saving non-destructive adjustment layer editing. (Its non-destructive editing is one of the best reasons to use Photoshop/Lightroom) GIMP doesn't offer non-destructive editing.
Photoshop is ahead of GIMP in introducing its latest tools and updates. GIMP can take a long time, in some cases, years, to add new tools.
Photoshop is excellent for graphic designers and offers CMYK support while GIMP doesn't. GIMP only processes using RGB. To convert any of your images in GIMP to CYMK, you will have to add a separate plugin.
Photoshop was built with graphic designers in mind, and then photographers began picking it up as editing software. It offers more tools for a spectrum of needs, including design and illustrating.
As an open-source program, its user interface isn't as professional as Photoshop's. (Of course, that means beginners might find GIMP easier to use.)
If you use smartphone editing, then it's Photoshop. Gimp doesn't have mobile capabilities.
GIMP, however, is smaller and takes up a lot less space on your laptop.
In Photoshop, you can quickly send images between other Adobe programs like Lightroom. The applications track all of your changes/edits across the platforms. GIMP only opens PSD files that you'll need to export and save onto your desktop, then reopen in the software.
Photoshop does a terrific job frequently updating the program, especially now with the Creative Cloud through offered downloads. It's superior to GIMP in this respect, even though GIMP also provides regular updates.
Photoshop pretty much beats everyone with its customer services.

If you need a pro-level, high-use photo editing software, then Photoshop will likely meet your needs better than GIMP. However, GIMP is good, free editing software that comes close to doing what Photoshop can do - but falls somewhat short.

If you're new to both photography and photo editing and are looking for something free and willing to accept fewer tools, GIMP might work for you.