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All site configuration is divided in three main layers - global, type and site. They are hierarchical and meant as overrides from one layer to another. This means that global is baseline for all sites, type is a subset of common overrides for a number of sites with common configuration patters (e.g. similar hardware, or need of enabled features), and finally the site is the last layer of site specific overrides and configuration (such as specific IP addresses, hostnames, etc). See Deckhand documentation for more details on layering.
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