How to pin IPFS files on Infura
Pinning in IPFS allows you to tell IPFS to keep a certain object in its storage. Usually, an IPFS client only keeps files cached for a certain time after they've been accessed, after which they get deleted during garbage collection unless you pin that file.
Pinning With Infura
Take a look at the following articles to learn more about pinning objects on IPFS with Infura: