This page is currently under construction
Singularity is a containerization technology, similar to Docker, originally developed at Lawrence Berkeley National Lab with the requirements of scientific computing and high performance computing (HPC) in mind, especially security. A company called Sylabs has since been started and continues to maintain and update Singularity (see the GitHub Repository). In addition to this page, you may want to explore the official documentation.
Please note: this documentation uses examples tested with version 3.3.0