There are two main types of fire extinguishers, carbon dioxide and dry chemical (powder)
Often, but not always, they carry different colors. In this case the carbon dioxide extinguisher is red, and the dry-chemical (powder) extinguisher is yellow. Read the tag to know which you will use. The tag also should show the date the extinguisher was last serviced. Carbon dioxide extinguishers are good, general purpose extinguishers. Dry-chemical (powder) are used for difficult cases, say certain types of electrical fires.
AVOID using a dry-chemical extinguisher on a fellow human being. The powder may get in the victim's eye and cause irritation.
Locate the "KEY" (the round object) Twist the "KEY" to break the stiff Nylon retaining cord then pull "KEY" out Do not merely attempt to pull the key straight out, unless you are very strong.
Raise the nozzle in order to direct the stream of carbon dioxide The CO2 will cool the fire, and restrict oxygen. The fire, lacking oxygen, should go out.
Squeeze the handle to begin operation.