Cosmos is a decentralized network for blockchains that connects different blockchains (cryptocurrencies) and allows them to trade with each other.
Cosmos allows separate blockchains to communicate with each other. Individuals each have their own computer and Cosmos acts as an IPS/re-layer. This is why Cosmos is called the "Internet of Blockchains".
Cosmos solves the scalability problem by connecting all blockchains on its network and making them interoperable, allowing transactions between different blockchains. Cosmos solves the scalability problem by connecting and interoperating with all blockchains on its network, and also enables transactions between different blockchains.
Another attractive feature is the ability to easily create decentralized applications (DApps) on its own blockchain using programming languages such as Java, C++, and Go.