SiaCoin is a token launched by the company Sia. Sia could be compared to Dropbox or Amazon cloud, and it works by splitting apart and encrypting your files across a decentralized network. With this method, you hold your own private key, and therefore you are the only person who has access to your data.
This makes Sia different to other cloud services, as no outside company can access of control your files, unlike before. Sia is also a lot more affordable, up to 10 x cheaper than some cloud services. It is also open source and built on the blockchain, which gives it the ability to expand rapidly and scale effectively.
SiaCoin has been doing very well in the cryptocurrency space, and the market cap has gone from $100 million to $500 million in just under a month. There is a good chance that companies will see the efficiency and cost-effectiveness of Sia, and will begin to migrate.