Most altcoins will be layered on Bitcoin eventually.

While bitcoin is still mainly seen as digital currency, it’s essentially a timestamped log with special properties.

As such, it can be utilized for far more things than payments and store of value. I presented some of the alternative uses several years ago and the list continues to grow.

Brian Deery, chief scientist at Factom, wrote an excellent history of timestamping, in which he argues that a secure timestamped record wasn’t feasible before the existence of secure digital value. -- Jameson Lopp

Bitcoin: The Trust Anchor in a Sea of Blockchains

Bitcoin software engineer Jameson Lopp takes a deep and enlightening dive into the unique attributes that make up blockchains.

https://www.coindesk.com/markets/2016/07/23/bitcoin-the-trust-anchor-in-a-sea-of-blockchains/