Ethereum is a public, open-source, blockchain-based distributed computing platform and operating system featuring smart contracts.1 Using a consensus algorithm it provides a decentralized platform for applications that run exactly as programmed without any chance of fraud, censorship or third-party interference.2 Blockchains do this by building a ledger which is a collection of blocks. The collection uses cryptographic hashes, a difficulty algorithm, and a process of "chaining" these blocks together to form this secure decentralized network.
A smart contract is a digital process which aids in verifying and enforcing a contract/agreement. This feature allows blockchains like Ethereum to take on additional computational complexity. CryptoKitties is a smart contract developed by Axiom Zen which employees a method to create unique artwork based around a game-play of breeding these digital assets to produce new ones.
Ethereum's transaction fees differ by computational complexity, bandwidth use, and storage needs. This is different then bitcoin which uses transaction size alone. Average gas prices fluctuate on ethereum network depending on the volume of traffic and how much people are willing to pay to have their transaction processed sooner.
Blockchains require a number of tools to work with, explore, and understand. A blockchain explorer is the primary tool that helps a user visualize the blockchain. Different blockchain explorers focus on different challenges with visualizing this data and thus can be helpful for fully understandings the Ethereum network.
Etherscan is the most common and popular ethereum blockchain explorer. Used to collect information about a specific wallet or contract address, as well as specific transactions. Contract details can be uploaded by contract owners and the CryptoKittiesCore provides an example of this. A small comments section is also provided.
Ethplorer is an alternative explorer that focuses more on at-glance stats and graphs of a given account.
EthGasStation provides a good overview of gas prices and wallet addresses which are filling the greatest percentage of transactions on a block.
EthStats has high level statistics about the health of the ethereum network, including block propagation times, gas spending, gas limits, block times, changes to difficult, and more.