The Dashboard service provides a graphical user interface for end users and administrators, allowing operations such as creating and launching instances, managing networking, and setting access controls. Its modular design allows interfacing with other products such as billing, monitoring, and additional management tools. The service provides three basic dashboards: user, system, and settings.  

It looks a lot like ...

The Compute service is the heart of the OpenStack cloud by providing virtual machines on demand. Compute schedules virtual machines to run on a set of nodes by defining drivers that interact with underlying virtualization mechanisms, and exposing the functionality to the other OpenStack components.  

Compute interacts with the Identity service for authentication, Image service for images, and the Dashboard service for the user and administrative interface. Access to images is limited by project and by user; quotas are limited per project. The Compute service is designed to scale horizontally on standard hardware, and can download images to launch instances as required.  

The Identity service authenticates and authorizes OpenStack users; the service is used by all OpenStack components. The service supports multiple forms of authentication including user name and password credentials, token-based systems, and AWS-style logins (Amazon Web Services). 

The Identity service also provides a central catalog of services and endpoints running in a particular OpenStack cloud, which acts as a service directory for other OpenStack systems.

Multiple services can be used as  the backed, including Active Directory, Red Hat Directory Server, Red Hat Identity Management, and OpenLDAP

The Image service acts as a registry for virtual disk images. Users can add new images or take a snapshot (copy) of an existing server for immediate storage. Snapshots can be used as back up or as templates for new servers. Registered images can be stored in the Object Storage service, as well as in other locations (for example, in simple file systems or external web servers).  

Supported Image Formats
raw (unformatted)
aki/ami/ari (amazon kernel,machine,ram images)
iso
qcow2 (qemu/kvm - supports CoW)
vhd (hyper-V)
vdi (qemu/VirtualBox)
vmdk (vmware)
ovf image containers

The OpenStack Networking service handles the creation and management of a virtual networking infrastructure in the OpenStack cloud. Elements include networks, subnets, and routers; advanced services such as firewalls or virtual private networks (VPN) can also be used.  

Because the OpenStack network is software-defined, it can easily and quickly react to changing network needs

The Block Storage (or volume) service provides persistent block storage management for virtual hard drives. Block Storage allows the user to create and delete block devices, and to manage the attachment of block devices to servers. The actual attachment and detachment of devices is handled through integration with the Compute service. Both regions and zones can be used to handle distributed block storage hosts

Can be backed by multiple storage backends, including Red Hat's Gluster and Ceph

The Object Storage service provides a storage system for large amounts of data, accessible through HTTP. Static entities such as videos, images, emails, files, or VM images can all be stored. Objects are stored as binaries on the underlying file system (using metadata stored in the file’s extended attributes, xattrs). The service's distributed architecture supports horizontal scaling; redundancy as failure-proofing is provided through software-based data replication.  

Extremely well-suited to multiple data center distribution due to nature of the topology.

Can be backed by multiple storage backends, including Red Hat's Gluster and Ceph, and Amazon's S3

The Telemetry service provides user-level usage data for OpenStack-based clouds, which can be used for customer billing, system monitoring, or alerts. Data can be collected by notifications sent by existing OpenStack components (for example, usage events emitted from Compute) or by polling the infrastructure (for example, libvirt).  

Telemetry includes a storage daemon that communicates with authenticated agents through a trusted messaging system, to collect and aggregate data. Additionally, the service uses a plug-in system, which makes it easy to add new monitors.  

Cloudforms is a great extension of this component. hint hint...

The Orchestration service provides a template-based way to create and manage cloud resources such as storage, networking, instances, or applications.  

Templates are used to create stacks, which are collections of resources (for example instances, floating IPs, volumes, security groups, or users). The service offers access to all OpenStack core services using a single modular template, with additional orchestration capabilities such as auto-scaling and basic high availability.

Cloudforms is a great extension of this too... hint hint.

Trove is currently very new and young. We want to mention it here because it also has the potential of being very awesome.