Excuse the bonehead post carbon dioxide is co2 duh yeah got a beginner here

In mig welding basics part 2 Jody spoke of common gases used with mig welding , like co2 , argon and 75/25 argon co2 also 90/10 . How about Carbon dioxide ? I have an old linde mig that has a carbon dioxide bottle attached with it how does this gas compare thank you.