$

$HOME
$PATH
$PS1
$HISTFILE
$SHELL

echo $YourVar
echo "$YourVar"

Related

• ${YourVar}
• Environment variables
• export

See also

• Variables: Environment variables, env, env-cmd, .env/, SHELL, PS1, HOME, PATH, HISTFILE, PWD, LD_LIBRARY_PATH, printenv, getenv, getenv, direnv, AWS cli environmental variables, envsubst, env:, env_file (docker-compose)