Chef is a popular configuration management tool used to automate the deployment and configuration of applications and systems. It is used to define the desired state of a system, and then it will automatically configure and maintain the system to match the desired state.
For example, you can use Chef to automatically install and configure a web server. You would create a Chef recipe that specifies the desired state of the web server, such as which packages to install, which configuration files to use, and which services to start. Once you have defined the desired state, Chef will automatically install and configure the web server to match the recipe.