what is deployment slot setting in azure

what is deployment slot setting in azure azure deployment slot setting Deployment slot settings have been removed Has anyone else experienced this or am I missing something? An Azure service that provides an azure deployment slot Here we will give an example of how to setup a Blue-Green deployment for an Azure Web App using Deployment Slots The scripts below assume

azure app service slot WEBSITE_SWAP_WARMUP_PING_PATH : The path to ping to warm up your site Add this app setting by specifying a custom path that begins with a slash