Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of fraud or third party interference.
Ethereum is a programmable blockchain. It means that developers can create applications on Ethereum.
These are called smart contracts. Smart contracts are decentralized applications that run on the Ethereum blockchain.
The most important feature of smart contracts is that they are unstoppable. Once a contract is deployed to the Ethereum blockchain, it will run exactly as programmed and there is no way to stop it.
This is because Ethereum is a decentralized platform which means there is no central authority that can take down a contract or interfere with its functioning.
This makes Ethereum ideal for running censorship-resistant applications. For example, a decentralized social network could be built on Ethereum where users are in complete control of their data and there is no way for a central authority to take the platform down or censor content.
Another use case for Ethereum is building decentralized financial applications. These are applications that run on the Ethereum blockchain and enable users to send and receive payments without the need for a centralized payment processor such as PayPal or Visa.
Decentralized exchanges are another type of financial application that can be built on Ethereum. These exchanges allow users to trade cryptocurrency without the need for a central exchange.
This means that there is no central point of failure which makes them much more resilient to hacks and attacks.
Ethereum is still in its early stages and many of these applications are still being developed. However, the potential for what can be built on Ethereum is immense and we are only just beginning to scratch the surface of what is possible.