> For the complete documentation index, see [llms.txt](https://calnix.gitbook.io/eth-dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://calnix.gitbook.io/eth-dev/ercs-and-eips/erc-20.sol/transfer.md).

# transfer()

### transfer()

![](https://cdn-images-1.medium.com/max/800/1*ATY-2GJJl4_yUHIZlbQJag.png)

transfer() is called on when we want to initiate a transfer of tokens **from ourselves (the function caller) to another address.**

* Moves `amount` tokens from the caller’s account to `recipient`.
* Returns a boolean value indicating whether the operation succeeded.

One usage of this would be in a dApp Vendor contract that sells ''yourToken'' for a price. The Vendor will transfer tokens from itself to the user when a purchase it made. For example, userA wants to buy tokens from a Vendor (service contract).

![](https://1628544884-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTgomzlmn9NrxUY0OQ3cD%2Fuploads%2F7nIIO8HWqlMeBjOxAfY2%2Fimage.png?alt=media\&token=d61a4af3-b51b-41e4-baab-8927bbd73c80)

* userA calls buyTokens() which is a function of the service contract (Vendor.sol), and sends some amount of ETH.
* after inventory checks clear, service contract calls token contract (yourToken.sol), instructing a transfer(*to =* msg.sender, tokenQty)
  * msg.sender -> userA, 
  * because within the scope of buyTokens(), caller was userA.
  * this gets passed on as a parameter object.
  * service contract is telling token contract that it wants to transfer tokens **to userA.**
* Inside the scope of transfer(msg.sender, tokenQty),
  * \_msgSender() -> service contract
  * because from Context.sol's perspective, \_msgSender was called by service contract. 
  * owner = service contract
  * *transfer(owner, to, amount) -> \_transfer(Vendor, userA, amt)*

transfer() calls two other functions, `_msgSender()` and `_transfer()`.

1. **\_msgSender()** 

\_msgSender() is inherited from Context.sol, which is an abstract contract, defined as follows:

![](https://1628544884-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FTgomzlmn9NrxUY0OQ3cD%2Fuploads%2F8RzWHmpgV3RipBtIoy31%2Fimage.png?alt=media\&token=d0767d47-f157-4a86-b6b0-12ab4c03eb65)

From `Context.sol`'s perspective, the function caller is the service contract, so msg.sender within this scope returns Vendor's address to be captured in `owner`. 

From documentation: 

> Replacement for msg.sender. Returns the actual sender of a transaction: msg.sender for regular transactions, and the end-user for GSN relayed calls

{% hint style="info" %}
If `a` wants to send 10 ERC-20 tokens to `b`, then `a` calls `transfer(b, 10)`. If `b` now checks his balance (e.g. because `a` informs him that he has just sent him 10 tokens), he will find that it has increased by 10 tokens. If your friends want to send tokens to each other, `transfer` is the way.
{% endhint %}