You are familiar with two different software tools called Yarn. You are not sure what they do or how they are different.
Solution / Yarn Disambiguation
This tool has an icon of a one-line drawing of a cat; the original Yarn website had other cat imagery, and there is the word "cat" in a yarn command. Our theory is that cats like to play with balls of yarn. This type of play can get out of control. Package managers make disparate and complex problems manageable. We do not think the etymology of this tool was that of a backronym.
We don't think resource negotiation is a factor or function of this Yarn. The product became quite big. This tool was released in 2016 (according to https://github.com/yarnpkg/yarn/releases/tag/0.2.0).
To learn more about it, see these postings:
Be advised we do not agree with the Wikipedia statement that this Yarn tool is an acronym.
To learn about the CLI, see this posting.
There is a separate tool called YARN that that is associated with Hadoop. Hadoop YARN is "[a] framework for job scheduling and cluster resource management" (as taken from https://hadoop.apache.org/).
The term YARN stands for "Yet Another Resource Negotiator" (according to TechTarget.com).
This tool was released in 2012 (according to Cloudera); it is part of the Hadoop framework. There is a GUI component to this tool as well as a command line component. To learn about the commands, see this external posting. To learn about the GUI, see this posting.
Products have been built on Hadoop YARN such as Tez; Tez is "[a] generalized data-flow programming framework, built on Hadoop YARN…" (according to https://hadoop.apache.org/).
To learn more about the sheer differences between the Yarn tools, see these postings: