Tangle (DAG) vs Blockchain
A Tangle is a novel technology concept that can mitigate most of the problems associated with blockchain based cryptocurrencies. Cryptocurrencies relying on a "Tangle" have no transaction fees, miners or blocks. Examples of Tangle based cryptocurrencies include IOTA and Byteball. With Byteball you can make safe contracts that will be executed exactly as agreed upon. IOTA is ideal for micropayments and "machine-to-machine" payments.