• The FOAM Map uses multiple smart contracts to enable a decentralized map without a central authority or single point of failure. 
• Each time tokens are transferred between contracts there’s a small fee charged by the Ethereum network, called gas, that fluctuates depending on how busy the network is at that time. 
• Approved FOAM and Voting Credit allow for your wallet to transfer to 2 different smart contracts. Doing this in advance helps to avoid more expensive gas and allows for fewer MetaMask confirmations and fewer chances that something can go wrong.