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## 1. contract address
1. Every Contract Account has a **unique address** determined when the contract was created.
2. The address is derived from the sender address and the transaction nonce (=number of transactions sent from that address)
3. Can receive **transactions** and processes them exactly as programmed to govern and advance its account **storage**, **balance**, **event log** and to send **message calls** (="internal transactions") to other accounts.

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## 2. binary code
Every Contract Account is controlled by the **binary code** which resulted from the processed transaction that created it.

It represents the EVM assembly code that was compiled from a corresponding **contract template**

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## 3. value balance
Every Contract Account has a **value balance** in wei
* 1 ether is `10**18` wei
* can be modified by sending transactions that include value

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## 4. storage
Every Contract Account has a persistant non-enumerable key-val-**STORAGE**
* **`256bit word`** keys => **`256bit word`** values
* costly to read
* more costly to initialize or modify
* can only be read and written to directly by the controlling contract

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## 5. memory
Every Contract Account has a **MEMORY** per "message call"
* linear and byte adressable
* width of 256 bits
* writes either 8bits or 256 bits wide
* reads or writes expand memory by 256bit words when accesing ountouched memory word
* expansion costs gas
* expansion costs scale quadratically

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## 6. stack
Every Contract Account has a **STACK** machine data area
* max 1024 elements of 256bit words
* can copy element of top 16 to the top
* can swap top with any of top 16
* all other operations take from top and push result on top
* possible to move stack elements to storage or memory to get deeper access

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## 7. event log
Every Contract Account has an event log.
* events can not be accessed by contracts after they have been created
* special indexed data structure mapping all the way up to block level
* allows efficient access from outside the blockchain (e.g. by Dapps)

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## 8. transaction history
Every Contract Account has a **transaction history** associated with its unique **`"smart" contract account address`**.

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