What does "a hundred rivers and a hundred shields" mean?

"Is the subject asking what a hundred rivers letter is?" Baichuanxin Baibaodun is a professional network security solution launched by Baichuanxin Information Technology Co., Ltd. Baichuanxin Information Service Co., Ltd. (hereinafter referred to as Baichuanxin) is an Internet platform company focusing on risk management. Baibaodun is a professional network security solution launched by Baichuanxin Information Technology Co., Ltd., which provides a secure network environment for enterprises. By adopting advanced technologies, such as firewall, intrusion detection system, intrusion prevention system, security audit system and security management system, network attacks can be effectively prevented and the network security of enterprises can be protected. Baichuanxin Baibaodun also has the functions of security audit and security management to ensure the security of the network system. It can not only detect malicious attacks in the network, and take timely measures to stop attacks, but also clean up enterprises' computers, delete useless files, caches and junk files, free up computer storage space and improve the running speed of computers.