Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of fraud or third party interference.

In order to achieve this, Ethereum uses a shared global infrastructure that runs the code of these contracts. This infrastructure is Ethereum’s decentralized virtual machine, which can execute code of arbitrary algorithmic complexity.

Ethereum’s decentralized virtual machine is called the Ethereum Virtual Machine (EVM). The EVM makes it possible for anyone to run any program, regardless of the programming language given enough time and memory.

The EVM is sandboxed and completely isolated from the network, file system or process of the host computer system. This allows for incredibly secure and robust smart contracts.

The EVM can be used to create all sorts of decentralized applications, including but not limited to: financial applications, social networks, voting systems, file storage systems, domain name registries and more.

What Database Does Ethereum Use?
Ethereum uses a custom-built database called LevelDB. LevelDB is a fast key-value store created by Google that uses an ordered mapping of keys to values.

Each key is associated with a value, which can be a number, a string or even another key-value pair. Keys are ordered lexicographically, which means that they are sorted alphabetically.

Ethereum is a decentralized platform that runs smart contracts: applications that run exactly as programmed without any possibility of fraud or third party interference.

These apps run on a custom built blockchain, an enormously powerful shared global infrastructure that can move value around and represent ownership of property. This enables developers to create markets, store registries of debts or promises, move funds in accordance with instructions given long in the past (like a will or a futures contract) and many other things that have not been invented yet, all without a middleman or counterparty risk.

The project was bootstrapped via an ether presale in August 2014 by fans all around the world. It is developed by the Ethereum Foundation, a Swiss non-profit, with contributions from great minds across the globe.

On traditional server architectures, every application has to set up its own servers that run their own code in isolated silos, making sharing of data hard. If a single app is compromised or goes offline, many users and other apps are affected.

On a blockchain, anyone can set up a node that replicates the necessary data for all nodes to reach an agreement and be compensated by users and app developers. This allows user data to remain private and apps to be decentralized like the Internet was supposed to work.

The Ethereum Virtual Machine (EVM) makes this possible even without a central server. Anyone can run an Ethereum node and take part in processing transactions on the network to earn ether, the cryptocurrency native to Ethereum.

Miners are rewarded based on their share of work done, rather than their share of the total number of blocks mined.

Decentralized applications have many advantages over traditional apps:

They are censorship-resistant: no single entity can shut them down.
They are fraud-resistant: there is no single point of failure that could be exploited.
They are tamper-proof: once deployed to the blockchain, they cannot be modified without consensus from all parties involved.

They are available 24/7: there is no downtime, and no need for maintenance windows.
Updates can be rolled out seamlessly: users do not need to download new versions or update their software.

In conclusion, apps built on Ethereum take advantage of the decentralized nature of the platform to provide users with censorship-resistant, fraud-resistant, tamper-proof applications that are available 24/7.

Layer 2 solutions are off-chain solutions that are used to scale the Ethereum blockchain. There are various types of Layer 2 solutions available, each with its own advantages and disadvantages.

The most popular Layer 2 solution is the Plasma framework, which allows for the creation of child chains that can be used to process transactions off-chain. Other popular Layer 2 solutions include the Lightning Network and State Channels.

Layer 2 solutions are important because they allow for scalability without sacrificing decentralization. This is because transactions are processed off-chain, which means that there is no need to wait for blocks to be mined in order to confirm a transaction.

This also reduces the load on the Ethereum network, as child chains can process transactions much faster than the Ethereum blockchain itself.

There are a few disadvantages to using Layer 2 solutions. The main disadvantage is that users have to trust the operators of the child chains in order to use them.

This trustless nature of Ethereum is one of its main selling points, so it is important to weigh up the pros and cons before deciding whether or not to use a Layer 2 solution.

Layer 2 solutions are a vital part of Ethereum’s scaling roadmap and there are a variety of different options available. It is important to research each option carefully before deciding which one is right for you.