Undercloud - The physical networking, bare metal hardware, and support services such as (ipam, domain controller, routing/switching devices, bare metal compute servers(gpu/cpu/fpga), network filters, and network attached storage).
IPAM - Internet Protocol address management - typically one’s DNS and DHCP but also includes tracking assignments, and address space, management of vlans, traffic management, QoS and the like.
Overcloud - Virtualized services, change items, and containerized applications. Basicaly if its an *-aaS then its inside the Overcloud.
Cloud - A vapor like mist that can contain finer particulates which coalesce into larger clustering of ephemerial parts. Also, marketing buzzword for virtual private servers and hypervisor technology.
Containers - A standardized containment of a product used in the life cycle for storage, shipping, and delivery of a product or service. See also docker, jails, and/or, LXC.
Domain Controller - An IPAM, netboot, and directory server for managing a cluster of computers from the network. Typically active directory which is an implementation of the following RFCs: 4511, 4120, 1002, 2131, 1035, 4514, 4578/5970, 6595.
PKI - Public Key infrastructure. SSL certificate keychains and certificate authorities (CA) for digital signatures, user management, access management, encryption, and identity management. Think facebook for computers and cypherpunks.
Private Cloud - an on premise or self owned space in a datacenter managing both the undercloud and overcloud.
Public Cloud - an IT marketing term for “someone else’s network, hardware, or datacenter”
DDNS - Dynamically assigned dns for change items, typically assigned at boot time or when accessible to the network.
DNSSD - Service Discovery standards using DNS to publish available services (ie http, ldap, ssh, etc.), thier ports, and priorities. Uses SRV, TXT, A, PTR and specialized names as defined in RFC-6763.
MDNS - Multicast dns which uses the multicasting instead of unicasting/broadcasting to query the network for distributed DNS records. While DNS-SD is implemented via normal unicast dns for static entries or dynamic via DDNS MDNS typically also includes both DDNS and DNS-SD.
Directory Name Services - the DS in DNS, and LDAP. This is an implementation of the x509 standards and can be seen used in PKI, LDAP/Domain controllers, and fully implemented DNS servers that include items from RFC 1183 such as RP, HINFO, LOC, and WKS (well-know services has been superseded by DNS-SD)
Directory - Container of information, either via physical or logical with a defined tree structure
