Terminology

Cluster Terms

Phrase	Definition
agent	A process running in server or client mode.
client/node	A Nomad client is responsible for running tasks assigned to it. A client registers itself with servers and watches for work to be assigned. When running the agent, the client may be referred to as a node.
server	A Nomad server manages all jobs and clients, monitors tasks, and controls which tasks get placed on which nodes.
dev_agent	The development agent is an agent configuration that provides useful defaults for running a single node cluster of nomad.

Phrase	Definition
task	The smallest unit of work in Nomad. Tasks are executed by task drivers like `docker` or `exec`, which allows Nomad to be flexible in the types of tasks it supports. Tasks specify their required task driver, configuration for the driver, constraints, and resources required.
group	A series of tasks that run on the same Nomad client.
job	The core unit of control for Nomad and defines the application and its configuration. It can contain one or many tasks
job_specification/jobspec	A job specification, also known as a jobspec.
allocation	An allocation is a mapping between a task group in a job and a client node. When a job is run, Nomad will chose a client capable of running it and allocates resources on the machine for the ask(s) in the task group defined for the job.