Ethereum

Dapps (decentralized applications)

As mentioned before, Ethereum offers developers a way to build applications on the block-chain. Applications build on Ethereum varies greatly, from games to financial applications to trading markets. 

The applications can be decentralized, meaning they run on a P2P networks of computers, instead of from a single server or computer. Unlike centralized applications, where a single server malfunctioning might bring down the whole application, decentralized applications would need the majority of its network to malfunction for the same thing to happen. 

Decentralized applications also make it very hard for hackers to breach the system, as the hackers would have to target the whole network of computers, instead of just a few or a single server. 

Smart Contracts

Ethereum allows for setting up smart contracts. Like normal contracts, where the terms of the contract are agreed on before signing, a smart contract only executes if the contract terms are met. 

For example: 

Your friend is going on a holiday trip to the other side of the world on the 1st of June. Because your friends birthday (5th of June) will be while hes on holiday, you want to send him some cash so he can celebrate. 
You setup a smart contract to send your friend 1 Ether on the 5th of June. 

The 5th of June arrives, and the smart contract automatically sends your friend 1 Ether.  

This is of course a very simple example. Imagine the possibilities when setting up more complicated smart contracts, or smart contracts that will trigger other smart contracts. A whole networks of smart contracts can allow for very complicated actions to take place automatically. 

Payments

Like Bitcoin, Ethereum offers its users to make payments using its cryptocurrency Ether. 

Ether makes it easy to send and receive payments across borders, and allows people to trade goods and services whitout needing middlemen suchs as banks and financial institutions. This greatley reduces fees during transactions.