Creating a multilingual website is more than just translating the content. All of the usual website development rules apply, plus the fact that everything exists in duplicate or triplicate, or exponentially more, depending on how many languages you are dealing with.
Drupal’s back-end deals well with this complexity. It maintains relationships between the different versions of each page. It can keep translations of your category names. And if you want it to, it can even offer its back-end administrative interface in other languages besides English.