Portable fire extinguishers come in two main types - cartridge type and stored pressure type. They are a first aid method for fighting small fires but have limitations in capabilities. It is important to use the right type of extinguisher for the specific fire. Extinguishers come in various classes suited to different types of fires. They have key parts like handles, nozzles and pressure gauges. It's important to remember the PASS method for operation - Pull, Aim, Squeeze, Sweep. Fire extinguishers should be used from a maximum effective range of 10-15 feet from the fire.