GIMP easily deals with all the major graphics file formats such as GIF, JPG, PNG, PSD, TIFF, and BMP. Additionally, GIMP uses a "native" format of its own known as the .XCF graphic format.

While working on a project in GIMP, it is strongly recommended that you save using the .XCF format. Once you have completed a project, you can then save or export in other formats.

I would further recommend that you always keep an .XCF copy of every graphic you have created so that it can be edited in the future.

CHECK YOUR UNDERSTANDING:
Download the GIMP Splash screen file provided. Save it in .GIF, .JPG, .BMP and .XCF formats. Notice the size and quality differences between the various graphic file formats.