TRON also has the concepts of RAM and CPU, which are its “Bandwidth” and “Energy” respectively. Bandwidth refers to the bytes of the transaction, for example, a transaction of 200 bytes will consume 200 bandwidth. Energy refers to the resources consumed for executing a smart contract, for example, a smart contract that requires 100 μs for its execution will consume 100 energy. All transactions consume bandwidth, including transfer and calling smart contracts. Some transactions require energy, such as calling a smart contract (TRC-20 transfer and in-dApp use). Consumed bandwidth and energy will be renewed after 24 hours. After you have used up your energy, you need to pay TRX as gas fees for transfers.