Running the Ethereum syncing node does not necessarily is for participation within the ethereum node network; most of the people in the network probably transact using wallets made on 3rd party wallet managers like MyEtherWallet or Coinbase and simply look at EtherScan to see when their transactions have occurred. This is convenient and probably secure but it’s not in the spirit of cryptocurrency.

Ethereum testnet

Public testnets for various cryptocurrencies are available to everyone, they're connected to the internet. Anyone can connect at any time, even from popular wallet interfaces like MyEtherWallet or MetaMask.

The following public testnets are available:

Ropsten
Rinkeby
Kovan

Types of Sync Methods

Before getting into what happens in the syncing process, it’s more important to know that how many ways you can sync a node.

There are the following ways in which you can sync the node.

Full Sync: this method uses the node that will replicate the blockchain state from the starting genesis block. This will download every transaction which is ever made on the ethereum network and computes the state of the transaction.

Fast Sync: this method will download the block headers and a recent state trie from peers who are already on the ethereum network. This will Only validate state transitions after it has been synced to a certain block height.

Warp Sync (Parity only): this method will download a set of files from the Parity peers that are on the network that contains all block headers and the state trie at a certain block height. This method Significantly reduces the number of requests that are needed to be made over the ethereum network. Similar to the Fast Sync method, these nodes will only start to validate state transitions after a certain block height.