E-cash is a digital payment method that allows online transactions without the need for physical cash. It is also known as electronic cash or digital money. However, there are several synonyms that can be used to refer to this payment system. Some of these include e-wallet, digital currency, virtual money, and crypto-currency. E-wallets are commonly used for in-app purchasing or online shopping while digital currency like Bitcoin, Ethereum, and Litecoin have gained popularity due to their decentralised nature. Virtual money includes any digital currency that is not regulated by a government, while crypto-currencies are encrypted digital currencies that rely on blockchain technology. Ultimately, all of these synonyms refer to the same concept of electronic currency that can be used for online transactions.