1An honorific/polite/humble prefix attached to words to show respect, politeness, or warmth — most commonly attached to kun-yomi (native-Japanese-reading) words: お茶, お名前, お元気, お祝い, お父さん. For on-yomi (Sino-Japanese) words, ご is used instead. The reading おん is a more formal/literary variant that survives mainly in fixed expressions like 御中 (used on formal envelopes) and 御礼. The prefix is almost always written in kana today, though the kanji 御 appears in formal documents.
お名前を教えていただけますか？
May I have your name?
お茶でもいかがですか？
Would you like some tea?
お父さん、ただいま！
Dad, I'm home!
今日はお疲れさまでした。
Thank you for your hard work today.
封筒の宛名は「株式会社〇〇 御中」と書きます。
On the envelope, address it as 'Company XX 御中' (a formal honorific used for organizations).