Toptal

Linux namespaces make it possible to run a whole range of applications on a single real machine and ensure no two of them can interfere with each other, without having to resort to using virtual machines. In a single-user computer, a single system environment may be fine. But on a server, where you may want to run multiple services, it is essential to security and stability that the services are as isolated from each other as possible.

Source: Toptal