Test networks exist to ease development and provide developers and companies an easy solution to deliver their product on networks that are not exchanging real value but providing the exact same service.
There’s multiple test networks available out there and this article will help demystify what are the big differences between each of them. We’ll be covering the main 3 which are:
Note that all ethers within those networks are not worth anything since this is only for testing. You can use any decentralized application that is connected to either one of those networks without having to worry about losing real money.
Ropsten is the one that most resemble the main network because it use a similar “Proof of work” consensus algorithm, meaning that nodes are in charge of maintaining the network. They use computing power to generate blocks and keep the blockchain up to date. Blocks are introduced at an average of 30s and this network is supported by both Geth and Parity. You can explore the chain using this link.
On this network the consensus algorithm differ’s a bit of the latter one, because it uses something called “Proof of Authority”. This consensus means that you need to prove your existence in order to retrieve ethers from a faucet. All ethers are already mined and only distributed on demand. Proving your existence is as easy as posting something on social media and using a link to prove you’r indeed real. Blocks are generated at intervals of 15s and this network is only supported by Geth. You can explore the chain using this link.
It’s consensus algorithm is the exact same as the Rinkeby network, which is a “Proof of Authority”. All ethers are also already mined and retrieval is also done via a faucet. There’s an advantage to using a POA consensus because they are immune to spam attack. No one can DDOS the network and annoy everyone that is using it. Ropsten was once attacked and it causes a whole lot of problems. Block on the Kovan network are generated at intervals of 4s and this network is only supported by Parity. You can explore the chain using this link.
As I stated before, those three networks exist to help developers test their own solution before going live on the main network. The majority of decentralize applications uses them during development or for their Alpha and Beta release.
Feel free to write a response if I’m wrong about something or there’s a need for some clarification.