When a user sends using the pubkey address, it's important to note that Stellar uses memo ID’s. You can think of a memo ID somewhat like the destination tags in XRP. Each time you need a new address for your wallet, you will need to use a new memo ID instead. When sending to other platforms, they will provide you with their pubkey address and a memo ID (usually unique to you specifically) that will identify the transaction as originating from your wallet. Memo IDs are only bound to the account because we use them as payment identifiers. In fact, they are only extra information that you can add to the transaction.
Memo IDs can also be used in conjunction with a Stellar address.