Focus on the pronunciation of firewall
English definition of “firewall”
/ˈfaɪəwɔːl/ noun [C]
› IT a computer system or program that prevents someone from seeing or using information on a computer without permission, especially someone using the internet: Without a firewall, all your files could be instantly accessible to any competent hacker from anywhere in the world.
› BANKING, FINANCE a way of making sure that one part of banking does not affect another by separating the operations of the two, especially so that investment banking should not negatively affect the banking sector that ordinary people use: One banking executive stated, "Creating a firewall between retail and investment operations may not be as simple as it first seems".