It's better than some of Photoshop's selection tools GIMP's Foreground Select tool doesn't get enough love, but it's one of the software's best secret weapons, unlike Photoshop's Quick Select and ...

Select a portion of the image you wish to preserve using the appropriate selection tool. There are six selection methods in GIMP: rectangle, ellipse, free, fuzzy, color, scissors and foreground.

If you can’t select the foreground objects or the background, you can’t edit much of anything. GIMP has seven Selection Tools, while Photoshop 2020 has ten.

GIMP 2.6 provides a "Color Picker Tool" that samples a small section of your image file. This color sample selected as a foreground or background color can then be copied to another part of the image.