This article provides an in-depth analysis of the concept of gwei in Ethereum and its importance in transaction costs and network resource allocation. Gwei is a unit of measurement for gas fees, and the gas fees paid directly affect transaction speed and cost. By understanding gas, gwei, and market dynamics, users can trade more efficiently and master practical strategies to reduce expenses. In the future, with the development of Layer 2 technology, gas fees will be significantly reduced, but the role of gwei as a pricing unit will continue to exist.