Just a small document to help me remember which ubuntu commands do what on my server.
./ - To run a .sh file or other executable I believe.
chmod - changes permissions, -r for everything.
cd - changes directory, .. goes up one, / to root, blank or ~ goes to home, - to last directory.
rm - remove specificed folders/files, use -rf to delete all files and subdirectories.
sudo shutdown -r now - restarts the server