Always there is a balance in nature, even in blockchains. If you want to have extra features, you need to make a sacrifice from your current features. For example to have high speed and volume; you need to give some from your security & immutability by doing consensus with smaller groups or you need to use different methods in consensus like POS / PBFT. (Proof of Stake / Practical Byzantine Fault Tolerance)
Plasma, a project by Ethereum, uses this side chain concept. It encourages transactions to happen on side chains (or child chains). An authority governs each of the child chains. If the authority starts acting maliciously, anyone on the child chain can quit the child chain and take back their pegged assets on the main chain. It’s in its early stages of development but shows a lot of promise in handling some of Ethereum’s scalability issues.
“Such brazen theft would indicate [1] that Bitcoin would be (in the near future) without sidechains of any kind, and [2] that Bitcoin itself may be in danger from the miners (and we may need to consider using an alternate proof-of-work hash function),” he explained the impact of this setup in his original post on the topic. Like SPV sidechains, drivechains require a soft-forking change to Bitcoin.
Ardor is a blockchain platform predicated on childchains (sidechains) that use proof of stake (PoS) consensus. It uses the primary chain as a security chain and the childchains for processing transactions to increase scalability. Their design is specifically focused on speed and efficiency through PoS consensus and removing blockchain bloat through pruning.
Forbes reports that blockchain and biometric eyeball scanning technologies underpin the systems that support food distribution in the Syrian refugee crisis. While there are many further uses of blockchain, at the core of its business functionality is the creation of transparent, stacking “ledgers” of information. This is where private blockchain can prove extremely useful.
Another technology that could see more widespread use in the coming years is side chains. A side chain is defined for one specific use case. There can be multiple side chains where different tasks are distributed accordingly for improving the efficiency of processing. Maybe one application needs to optimize for high speeds and another needs to optimize for large computations. In any case, side chains can be used to handle commercial blockchain usage. CryptoKitties would have greatly benefitted from an optimized high-speed side chain. At one point, they jammed up the Ethereum blockchain with 25% of all transactions coming from their application.

There are many critics of payment channels. Finding the quickest path between unconnected nodes is no trivial exercise. This is a classic “traveling salesman” problem that has been worked on by top computer scientists for decades. Critics argue that it is highly unlikely payment channels like Bitcoin’s Lightning and Ethereum’s Raiden will work as expected in practice due to complexities like the traveling salesman problem. The key for you is just to know that these projects and potential solutions to blockchain scalability issues exist. Many of the smartest minds in the industry are working actively to bring them to life.

^ Jump up to: a b c d Bhaskar, Nirupama Devi; Chuen, David Lee Kuo (2015). "3 – Bitcoin Mining Technology". In Cheun, David Lee Kuo. Handbook of Digital Currency: Bitcoin, Innovation, Financial Instruments, and Big Data. Academic Press. pp. 47–51. ISBN 978-0-12-802117-0. Archived from the original on 25 October 2016. Retrieved 2 December 2016 – via ScienceDirect.

Let me explain. The Lightning Network allows for the creation of “micropayment channels” across which multiple Bitcoin transactions can be securely performed without interacting with the blockchain, except for the initial transaction that initiates the channel. There is no counterparty risk: if any party ceases to cooperate, and/or does not respond within an agreed-on time limit, the channel can be closed and all its outstanding transactions kicked up to the blockchain to be settled there.
The great thing about Bitcoin, for a tech columnist like me, is that it’s simultaneously over-the-top cinematic and technically dense. Richard Branson recently hosted a “Blockchain Summit” at his private Caribbean island. There’s a Bitcoin Jet. At the same time, 2015 has seen the release of a whole slew of technically gnarly–and technically fascinating–proposals built atop the Bitcoin blockchain.
I said above that you can build sophisticated rules into Bitcoin transactions to specify how ownership is proved. However, the Bitcoin scripting language is deliberately limited and many ideas in the Smart Contracts space are difficult or impossible to implement. So projects such as Ethereum are building an entirely new infrastructure to explore these ideas
Since 2008 when Satoshi Nakamoto published a white paper considering Bitcoin and blockchain technology, the latter gained fame as a tool for combating trust issues and bringing transparency to transactions between independent participants. Even though a decade passed, for a lay public, blockchain is still not the easiest concept to deal with. As a rule, people generalize things they don’t understand deeply in detail. Thus, when they hear “blockchain,” they tend to think there’s just one transcendental blockchain that hosts thousands of projects. But it’s a wrong perception as there are numerous blockchains and they differ.
Function Transactions executed between the locks and unlocks of the main chain tokens don't bloat the main chain. As the technology of a side chain is connected to its main chain, it can be used to build on the developments of the main chain and introduce new features to the market. Child chains serve as the transactional chains of the parent-child architecture, as the parent chain retains minimal features.
Sidechains are an essential innovation in the blockchain field with some interesting long-term implications and effects on the broader interoperability and scalability of blockchain networks. They are effectively extensions of existing blockchains that increase their functionality and allow for validation of data from other blockchains and for assets to be seamlessly transferred between them.

Sidechains solve a lot of problems, but at what cost? The introduction of sidechains makes things even more complex and much harder to understand for those who are not actively involved in the blockchain space. This also divides assets, no more “one chain, one asset” adage, which further complicates things. And on a network level there are multiple independent unsynchronised blockchains interacting with each other.

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Por lo tanto, y gracias a estas sidechains, se podrían conectar a Bitcoin soluciones con objetivos concretos, complementándole y aprovechando sus ventajas pero con la suficiente independencia. Para ello se usan unas piezas llamadas ‘two-way peg’, que son las encargadas de sincronizar las transferncias (validan y inmovilizan las monedas) entre ambas cadenas: la sidechain cuenta con unas monedas ya minadas pero sin dueño a la espera que, tras el intercambio, queden bajo el control del usuario que llega a esta cadena.
The information on every public blockchain is subsequently replicated to sometimes thousands of nodes on the network. No one power administers it centrally, hence, hackers can’t destroy the network by crippling one central server. Read this article “What is Blockchain technology? A step-by-step Guide For Beginners”, for a more detailed description of the technology.
A partir de este momento, se podrán intercambiar y mover estas monedas para hacer uso del potencial de esa sidechain siguiendo las directrices y protocolo que ésta tenga estipulado. Por ejemplo, quizá la velocidad de creación de los bloques es más rápida en esta o quizá los scripts de transacción en esa cadena son turing completos (disponen de un poder de cómputo equivalente a la máquina universal de Turing).
The ethereum-based app builder has a dedicated team of experts looking at all varieties of fiat cash on distributed ledgers, and it's working with UnionBank of the Philippines to create a low-cost tokenized fiat solution for rural banking. In time, this could be extended to cover a larger network of banks and perhaps even the central bank, ConsenSys says.