What is the difference between a gas mask cartridge a canister and a filter?

A gas mask cartridge is a self-contained unit that combines a filter and other components to remove harmful substances from the air, typically used in military or industrial settings. A canister is a type of cartridge that specifically contains absorbent materials for filtering out gases and vapors, often used for more complex chemical threats. In contrast, a filter is a broader term that refers to any device or material that removes particulates or contaminants from the air, which can be part of a cartridge or separate. Essentially, all canisters and cartridges contain filters, but not all filters are part of canisters or cartridges.