Scalability has been a problem with crypto-currencies since Bitcoin’s introduction.
Scalability is the capability of a system, network, or process to handle a growing amount of work, or its potential to be enlarged in order to accommodate that growth.
In order to resolve this, Lisk will become the first truly modular crypto-currency by utilizing sidechains as a solution to scalability. Lisk sidechains allow us to implement various features into the Lisk main network simply as Decentralized Applications (Dapps). This not only makes single features optional, it will also keep the Lisk mainchain streamlined in comparison to other crypto-currencies.
From an architectural standpoint it is rational to apply this modularity prior to the official Lisk launch. Therefore, effective immediately, we have completely removed the current implementation of usernames and contacts from Lisk. In the near future, they will be part of the so called “Core Dapps” which bring new features directly integrated into the client user interface (UI).
The first Core Dapp allows users to create a unique identity on the Lisk network involving information such as username, first name, surname, email, forum/chat username, and/or a description. Dapp developers are be able to access the identity sidechain and use the information within their own dapps, e.g. the name of a Lisk account owner.
Alongside with the other planned Core Dapps (messaging, dapp reviews/ratings, contacts), Lisk not only becomes a decentralized network, it becomes a feature-complete and independent ecosystem. Combined with the many dapps by our users Lisk will form a one of its kind hub for the world, empowering the Internet of Things and motivating many industries.
https://blog.lisk.io/lisk-the-first-modular-crypto-currency-dd3e8df87613
Looking forward to this.