Basic-Concepts
Web Servers
Uptime
Internet
Programming
Version Control
Configuration Management
Virtualization
Databases
Mail Servers
Domain Name Servers
Some useful links to explain the concepts of Ruby
https://www.ruby-lang.org/en/documentation/
https://ruby-doc.org/
https://stackoverflow.com/questions/15708916/use-rvmrc-or-ruby-version-file-to-set-a-project-gemset-with-rvm
https://stackoverflow.com/questions/4667150/what-is-the-best-way-to-uninstall-gems-from-a-rails3-project
https://dev.to/molly_struve/how-to-setup-a-readonly-rails-console-1j1a
http://syndicode.co/2018/01/29/books-and-tutorials-for-learning-and-mastering-ruby-language
https://stackoverflow.com/questions/14289217/im-getting-rvm-is-not-a-function-error-on-mac-os-x-and-no-posted-solutions-w
https://www.exceptionalcreatures.com/bestiary/Net/OpenTimeout.html
https://dev.to/exampro/testunit-writing-test-code-in-ruby-part-1-of-3-44m2
http://engineering.pivotal.io/post/debugging-ruby-memory-issues-cloud-foundry-cloud-controller/