Difference between IPFS and Filecoin?

Question

They both seems to store files in a decentralized network. So what's the difference between them in terms of data structure and algorithms they use? And also what's the difference between them in terms of use cases?

If I store a file in IPFS or Filecoin, will it remain there forever or it may get lost?

Answer 1

There is no proper way to differentiate between Filecoin and IPFS as Filecoin simply runs on top of IPFS. While IPFS enables storage and content-based addressing, Filecoin is mostly leveraged to incentivize users for curating content into IPFS. 

There is no structural or architectural difference between them because both of them work on different levels in a blockchain network.