When Maya 2018.6 was released, it created a strange situation where an update for an older version of the software was reportedly than the then-current flagship, Maya 2019.
Maya 2018.6 was released around late 2018. Since then, Autodesk has moved to newer versions (2020–2025). The .zip file you have may be an installer archive or a portable version. For production use, consider updating to a supported release. Autodesk Maya 2018.6.zip
Features like the MASH nodes for creating complex procedural animations and motion designs. When Maya 2018
Interestingly, some users reported that 2018.6 actually felt for certain tasks than the then-new Maya 2019. Workflow Refinements: When Maya 2018.6 was released