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IPFS Decentralization & Content Addressing

Decentralization

Making it possible to download a file from many locations that aren't managed by one organization:
  • Supports a resilient internet. If someone attacks Wikipedia's web servers or an engineer at Wikipedia makes a big mistake that causes their servers to catch fire, you can still get the same webpages from somewhere else.
  • Makes it harder to censor content. Because files on IPFS can come from many places, it's harder for anyone (whether they're states, corporations, or someone else) to block things. We hope IPFS can help provide ways to circumvent actions like these when they happen.
  • Can speed up the web when you're far away or disconnected. If you can retrieve a file from someone nearby instead of hundreds or thousands of miles away, you can often get it faster. This is especially valuable if your community is networked locally but doesn't have a good connection to the wider internet. (Well-funded organizations with technical expertise do this today by using multiple data centers or CDNs — content distribution networks (opens new window). IPFS hopes to make this possible for everyone.)
That last point is actually where IPFS gets its full name: the InterPlanetary File System. We're striving to build a system that works across places as disconnected or as far apart as planets. While that's an idealistic goal, it keeps us working and thinking hard, and almost everything we create in pursuit of that goal is also useful here at home.

​#Content addressing

For a beginner-friendly primer on why cryptographic hashing and content addressing matter, take a look at ProtoSchool's tutorial, Content Addressing on the Decentralized Web (opens new window).
What about that link to the aardvark page above? It looked a little unusual:
/ipfs/bafybeiaysi4s6lnjev27ln5icwm6tueaw2vdykrtjkwiphwekaywqhcjze/wiki/Aardvark
That jumble of letters after /ipfs/ is called a content identifier and it’s how IPFS can get content from multiple places.
Traditional URLs and file paths such as…
  • https://en.wikipedia.org/wiki/Aardvark
  • /Users/Alice/Documents/term_paper.doc
  • C:\Users\Joe\My Documents\project_sprint_presentation.ppt
…identify a file by where it's located — what computer it's on and where on that computer's hard drive it is. That doesn't work if the file is in many places, though, like your neighbor's computer and your friend's across town.
Instead of being location-based, IPFS addresses a file by what's in it, or by its content. The content identifier above is a cryptographic hash of the content at that address. The hash is unique to the content that it came from, even though it may look short compared to the original content. It also allows you to verify that you got what you asked for — bad actors can't just hand you content that doesn't match. (If hashes are new to you, check out the concept guide on hashes for an introduction.)
NOTE
Why do we say "content" instead of "files" or "web pages" here? Because a content identifier can point to many different types of data, such as a single small file, a piece of a larger file, or metadata. (In case you don't know, metadata is "data about the data." You use metadata when you access the date, location, or file size of your digital pictures, for example.) So, an individual IPFS address can refer to the metadata of just a single piece of a file, a whole file, a directory, a whole website, or any other kind of content. For more on this, check out our guide to how IPFS works.
Because the address of a file in IPFS is created from the content itself, links in IPFS can't be changed. For example ...
  • If the text on a web page is changed, the new version gets a new, different address.
  • Content can't be moved to a different address. On today's internet, a company could reorganize content on their website and move a page at http://mycompany.com/what_we_do to http://mycompany.com/services. In IPFS, the old link you have would still point to the same old content.
Of course, people want to update and change content all the time and don't want to send new links every time they do it. This is entirely possible in an IPFS world, but explaining it requires a little more info than what's within the scope of this IPFS introduction. Check out the concept guides on IPNS, the Mutable File System (MFS), and DNSLink to learn more about how changing content can work in a content-addressed, distributed system.
It's important to remember in all of these situations, using IPFS is participatory and collaborative. If nobody using IPFS has the content identified by a given address available for others to access, you won't be able to get it. On the other hand, content can't be removed from IPFS as long as someone is interested enough to make it available, whether that person is the original author or not. Note that this is similar to the current web, where it is also impossible to remove content that's been copied across an unknowable number of websites; the difference with IPFS is that you are always able to find those copies.
This page is mirrored from the official whitepaper of IPFS: https://docs.ipfs.tech/concepts/what-is-ipfs/#decentralization​