A few things it can help to know before you write.
When you press Translate, your words go to Anthropic. That is where the translation happens. Your words do not stay here.
This site keeps a copy of the translated words for one day, so that if you type the very same thing again, it can answer right away.
The site remembers a little about each visit, such as how many times someone has used the site today, so it can rest when it needs to. It does not remember what anyone said.
Anthropic can keep what it receives for a while, as its own rules say. If that matters for what you want to say, it is okay to say it another way, or to wait until it feels right.