Architectural design terminology for non-combustible walls designed to prevent the spread of fire to adjacent areas with a耐火limit of not less than 3 hours. They are used to demarcate fire-resistant zones or as crucial separation elements to prevent the spread of fire between buildings. These walls can effectively contain the fire to a specific area during the early stages of a fire and during extinguishing efforts, blocking the fire from spreading from one side of the firewall to the other, playing a vital role in reducing fire damage.

Firewalls, along with common brick walls and floors, are fixed fire separation components; operable and closable types include fire doors, fire windows, fire curtains, and fire water curtains, etc.