The host.json file is a configuration file containing the values that affect all the functions of a function app. This file is created as soon as we add an Azure Function project. This file will have at least one field to begin with, indicating the runtime version of Azure Functions.
The following is the content of the host.json file created in our sample project:
To understand the various elements of a host.json file, please refer to the documentation: https://docs.microsoft.com/en-us/azure/azure-functions/functions-host-json.