In this and subsequent chapters, we will talk about a lot about concepts that might not be familiar to everyone. To make sure we're all talking the same language, let's briefly introduce and describe the most important of these concepts or words:
| Terminology | Explanation |
| VM | The acronym for virtual machine. This is a virtual computer. |
| Node | An individual server used to run applications. This can be a physical server, often called bare-metal, or a VM. A can be a mainframe, supercomputer, standard business server, or even a Raspberry Pi. Nodes can be computers in a company's own data center or in the cloud. Normally, a node is part of a cluster. |
| Cluster | A group of nodes connected by a network that are used to ... |
