Types of piping

I’m fairly new and I don’t have a construction background… so, I’m still a bit confused about the easy ways to tell the difference between:

painted/dirty copper piping,
galvanized steel piping,
painted galv steel,
black cast iron,
brass fixtures

Sometimes they can look similar or discolored so I find it rather difficult to be 100% certain.

look at fittings. the copper fittings are more stream lined. Gal is usually silver in color.

Here is a gallery of different pipe corrosion failures, and also shows different types of piping material that may help.

http://www.corrview.com/corr_07.htm

You may need to scrape some paint off in an inconspicuous area to see the surface. Don’t forget lead piping used as supply into homes is easily recognized because it is very soft and easy to scratch.

Also usually has a noticeable curve.