The InterPlanetary File System (IPFS) is a second layer protocol to access a decentralized web.
What does that mean?
Well let's start simple. The way the internet works normally is a back and forth between the user and a server. For example, if you want to visit google you type the address into your browser and it sends a request to the google servers to send you the web page. IPFS works on top of the current internet system by allowing users to be the web server. When a user wants to visit a web page they send out a request to the rest of the people on the IPFS network and the files are sent from those users to you. This means that you have a saved copy of any site, image, video, etc that you have viewed and can freely distribute this to anyone who is asking for it. This effectively makes censorship impossible by removing the ability of a centralized server host who can decide to remove content if it doesn't meet their approval.
How is IPFS different?
IPFS uses cryptography to create a unique identifier for every file being shared on the network. Because a file will always return the same identifier, it means that multiple copies of the same file wouldn't need to exist on the network. This ultimately saves on bandwidth for everyone. If you wanted to host a website on IPFS it wouldn't cost as much bandwidth to spread the information to the world as it would with a dedicated server host. Once another person has a copy of your site the next person asking to view it would have downloaded a partial copy from you and the first user. This becomes exponential over time simultaneously saving you huge amounts of bandwidth and creating worldwide backups of your site.
For a more indepth view of what IPFS is capable of, check out the Video and link below.