Around the time of the Azure DevOps rebrand everyone focused on the new name of the product (or suite of products)
What went slightly unnoticed was a change in what common entities inside Azure DevOps are called.

Here is a table listing them all out.

Previous Term New Term
Account Organisation
Organisation Enterprise
Hosted agent Microsoft-hosted agent
Private agent Self-hosted agent
Agent pool Agent pool
Agent queue Agent pool
Build definition Build pipeline
Build Build
Phase Job
Release definition Release pipeline
Release Release
Environment Stage
Concurrent job/pipeline Parallel job
Service endpoint Service connection

Notable changes included the simplification of the agent pool/queue principle, where everything is called a “pool” now.
There was also yet another rebrand of the way CI/CD jobs are charged for.

The move from phases to jobs and from environments to stages seemed to have been motivated by the fact that it was not obvious to users that environments are a logical constract rather than a proscriptive grouping. In many cases it makes sense to have two environments [now: stages] that deploy into the same “enviornment” [as in: inrastructure/network area].

Official Documentation