# Terms

BDeploy has a some important terms and concepts which should be known before diving into details of the application itself. These terms will be used all over the documentation to cross-reference other parts of the application.

Term	Meaning
Instance Group	An Instance Group is the main top-level element used in BDeploy. It provides a grouping of Instances (as the name suggests).
Product	A piece of software that can be deployed with BDeploy. A product is a bundle of Applications along with some meta-information.
Application	A part of a Product that can be started and stopped separately. Applications either run as Process on a server machine or as Client Application on a desktop computer.
Client Application	An Application that can be distributed on desktop computers.
Instance	An Instance is the actual deployment configuration of a Product. In one instance, the Applications of a Product can be distributed as Processes on one or more Nodes. The Product (and it's Applications) describes the possible configuration values (e.g. configuration files, command line parameters, etc.) - the Instance provides actual values for these.
Instance Version	An Instance Version describes the configuration state of an Instance at a given time. Each change that is done by the user results in a new instance version. Versions are immutable and cannot be changed. Each new change results in a new version of an Instance.
Process	A server Application that is configured to be started on one of the server Nodes of an Instance.
Build	A Build represents the immutable collection of all runtime artifacts (binary files, configuration files, templates etc.) of a Product. As a Build is immutable, the build tool (Maven, Gradle, Eclipse) creates a new one on every execution.
Product Version	A Product Version represents a Build that is marked with a Tag.
Tag	A Tag identifies a Product Version. The structure of a tag is defined by the Product itself. The only obligation is, that a tag has to be unique for different Builds of the same Product.
Node	A server machine (virtual machine or bare metal) that is used in an Instance to run the configured Processes on it. BDeploy supports Windows and Linux nodes, even mixed in one instance.
Minion	Agent process provided by BDeploy that has to run on every physical node used by BDeploy. In a multi-node setup one minion takes the role of a master. All others act as headless nodes which are managed by the master.
Deployment	The whole process of making one Instance Version up and running. This includes the major process steps: Installation, Activation, Process Control.
Installation	The process of transferring the configured Processes of an Instance Version to all Nodes of that Instance. The Installation makes this Instance Version available for its Activation.
Activation	The Activation marks a previously Installed Instance Version as the one to be started by the Process Control. Only one instance version can be active for one instance at the same time.
Process Control	The Process Control is responsible for starting, keep-alive and stopping the Processes of the active Instance Version.
System	A System is a bracket around multiple Instances using potentially different Products. A System is a logical group of individual pieces of deployed software.