When you need your computer to do a specific task like edit photos then you have to install software. Companies hire smart people to build software then charge you hundreds of dollars for it.
Open Source software is created by smart people who are nice. They share their programs freely so others can help improve them. Today there is an Open Source version of anything, even Photoshop!
Gimp is the Open Source version of Adobe Photoshop. You can download the latest version for either Mac or PC from
It would be impossible to cover all the features of Gimp in this guide but as you can see from this photo it has layers, transparency, masks, selection tools, paint brushes, etc.
Once you have Gimp installed you can work your way through training tutorials at the following site.
You can help the gimp community even if you aren't a programmer by testing the software, writing documentation, suggesting new features, giving kudos to the developers.