登録 and 更新: recording information and updating it
Compare registering an address with updating existing information, checking the updated field and any unfinished submission step.
Recording information in a register or system
登録, read とうろく, means recording information in a register or system. 連絡先としてメールアドレスを登録しました。 says that an email address was registered as contact information.
登録内容を確認してください。 asks someone to check the registered details. The earlier object or screen instructions identify what was registered.
Making existing content current
更新, read こうしん, means updating existing content or renewing a period of validity. 引っ越したので、登録した住所を更新しました。 says that the registered address was updated because of a move.
契約を更新するか、まだ決めていません。 says that renewal of the contract has not yet been decided. 更新 is not limited to editing information.
Entry and applying an update
新しい住所を入力しましたが、まだ更新ボタンを押していません。 says that the new address was entered, but the update button has not yet been pressed. This notice distinguishes entry from executing the update.
更新したのは住所だけで、電話番号は同じです。 says that only the address was updated and the phone number is unchanged. Preserve the scope of だけ.
Did the phone number also change in 更新したのは住所だけで、電話番号は同じです。?
Show the answer and why
No. Only the address was updated, and the phone number is stated to be the same.