From the exchange to the wallet
In the EOS account system, the account name is the billing address and is unique. Therefore, if you withdraw the EOS from the exchange to the wallet, you only need to submit the EOS account name to the exchange. Memo (remarks) is optional.
From the wallet to the exchange
If you are gonging to transferring the EOS to a centralized exchange in your wallet, you will need to fill out a memo (remarks). Because all exchange users share an address, Only the memo can distinguish user's assets.
If you fill in the wrong memo, please contact the exchange's customer service immediately for assistance.