Chef is primarily used for configuration management. For example, if you are managing a large number of servers (thousands or more), it is essential to ensure that the configurations across all servers are consistent. Otherwise, making any changes to the configurations would require writing a script to apply those changes across all the servers. Additionally, end-users may change configurations on multiple servers, leading to inconsistencies across different servers. To avoid this, configuration management is required.
We use Chef for this purpose by using a server-client mechanism. We apply changes to the Chef server, and every 30 to 40 minutes (depending on the configuration), Chef will verify whether the server has the required configuration. If not, it will revert to the required configuration automatically.