Question on erasing background on picture

Hi, I just been getting into Alpha channels/transparency, andd of course, on cars, or other things, you need to get rid of the useless background, i've been using the eraser, and it takes quite awhile. Is there anyway to erase the background by selection. For example if you have a black background, and need to get rid of it, you just select by colors and need to erase it, is there a faster way, than to manually erase it? It could save me alot of time.

I use Gimp, but also have Adobe Photoshop.

This is for GIMP version 2.2. I know Photoshop has equivalent tools, but I couldn't tell you exactly what they're called.

If the background is all its own layer, you can just turn its display off by clicking that layer's eye icon on your Layers panel. You can also delete that layer if you know you'll never need it.

The "magic wand" selector tool (looks like a wand, shortcut: z) will select entire areas that all have the same or similar color to the pixel you click on. The best thing about this tool is that you can slide the mouse around before you let the button go to adjust how close the colors have to match to be included in the shape. (You can adjust this setting manually, too, on the option panel that comes up when you double-click the wand, but it's not nearly as convenient.)

The "Select Regions by Color" tool (looks like a finger pointing at a blue pixel between a yellow and a red one, shortcut: shift-O) is similar to the wand, but it doesn't let you adjust the sensitivy on the fly, and it always searches the entire image for matching colors. The wand only searches outward for a single contiguous shape from the spot you clicked.

Both tools have more options, like whether to automatically smooth out the edges of the areas they pick. Double-click the tool's own icon to see and/or change its settings.