Language switcher without widget

Dear all,

I saw in the FAQ that I can use language switcher without widgets when I put a code in “Templates”. Unfortunately it is not clear to me what is this “Templates”. Obviously it is a file but where is it located? It is not in the root folder, not in wp-admin, nor in wp-content or wp-includes.

In wp-includes there is one file template.php but it is not “Templates”. So can you help me with resolving this mystery?

Thanks!