As all Emacs users probably know, one of the very basic Emacs concepts is the buffer. A few days ago I encountered an (admittedly, not very common) situation when this came in very handy.
Source: The benefits of everything being a buffer, an article by Marcin Borkowski.
I won't go into specific cases in this blog post. This is a general guide on how to gather the necessary information that will help you to get your problem fixed.
Source: SSH Troubleshooting Guide.
Screen is a terminal multiplexer and has a wide feature set. It allows you to split your terminal window into multiple windows (split screen feature), detach sessions to let commands run in the background, connect to a device via serial interface, and many more. Screen sessions keep running even if you disconnect, which is especially great for unreliable connections. There are more advanced use cases, but we will focus on the basics.
Source: Getting started with GNU screen.