# ExC Store/Reward Economics

ExC is a universal unit in ExtraChain blockchain. It has different usages:‌

* Store/Reward Farming; 
* Trading tool at ExC Automated Exchange; 
* Liquidity pool equivalent; 
* Universal synthetic asset measurement unit; 
* Universal equivalent for DApps interaction via ExC Store; 
* DAO governance (if DAO has no specific ExT); 
* Staking tool;

ERC20 ExTokens will be swapped to ExtraCoins according to roadmap.‌

![ExtraCoin Flow](https://3221710482-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M_e4X3B8j5J2bjX1pkg%2F-Ma2vqOO5fTfgxJ0AMJT%2F-Ma2x39V68aJ46vN7oqC%2FTD-25.png?alt=media\&token=e0e0a910-b931-4eea-8bb0-f645eb72161a)

“Store/Reward” system describes coin flow and network participant interactions and possible rewards for network support. System defines 3 roles:

* User - uses blockchain and ExDFS for personal needs and interacts with services and DrApps built by Service Providers;
* Service Provider - creator or maintainer of DrApp, that provides certain service for users;
* Storager - network participant that dedicates a part of their device memory for ExDFS support.

These system roles can be distinguished by the way they interact with ExDFS:

* User has access to their private directory of ExDFS and to service directories. User mostly stores own data, and uses selected directories and files to interact with services and DrApps.
* Service Provider operates their own directories and creates a space for users to interact.
* Storager only stores ExDFS files to support network.

To get a storage in ExDFS, users must do a "Fueling". This is an action of burning ExCoins to create a storage space. \
Fueling ratio is: 5 ExC = 1 GB at the launch of main network. \
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Burned coins also create conditions for Reward coins to be created and distributed between Storagers. Reward is based on size of storage provided for ExtraChain Network.