Files and directories on Unix-like systems (including Linux) are organized in to a tree. At the bottom (or the top, if you're a computer scientist—they have funny trees) is the trunk or "root directory". The path for that is
/. From that, you can build other paths:
/relazione is a directory that is immediately off the root.
Normally, your personal files are somewhere inside your home directory (typically
home is off of the root directory, then
username is off of
What you did isn't likely to break anything (though it may make it hard for you to find your files—e.g., if you use a GUI, it'll start looking in your home directory, or maybe even a directory inside that). If you're using a file indexer, those files will probably no longer be indexed. Etc. You can just move it back, with something like:
sudo mv -i /relazione ~/relazione
~/ is a quick way to specify your home directory (to save typing).
However, there is something that will break your computer: that habit of running things with
sudo. When you get an error trying to run a command, there is a reason for that! Permissions are there to (among other things) protect the system from destruction, and
sudo removes all restrictions. You should use it as sparingly as possible, and only when you understand the command you're about to run.