Landing page - Rewrite IPFS definition (ipfs#1442)

* Small change to landing page

* Rev. 2

* Linking to Usage ideas and examples

* Replaced Filecoin link with ecosystem directory

* small change to the wording

Author: TMoMoreau

docs/README.md

@@ -5,7 +5,9 @@ description: The home page for developer documentation for IPFS, the InterPlanet
 
 # Welcome to the IPFS docs
 
-The InterPlanetary File System (IPFS) is a decentralized file system for building the next generation of the internet. [Filecoin](https://filecoin.io) and many popular Web3 projects are built on IPFS. Some call it the hard drive for blockchain and Web3, though its power extends much further.
+The InterPlanetary File System (IPFS) is a set of composable, peer-to-peer protocols for addressing, routing, and transferring [content-addressed](concepts/glossary.md#content-addressing) data in a decentralized file system. Many popular Web3 projects are built on IPFS - see the [ecosystem directory](https://ecosystem.ipfs.tech) for a list of some of these projects.
+
+While IPFS is a file system, it is _not_ a storage system. Instead, IPFS can be thought of as both the protocol implementations of IPFS (such as [Kubo](concepts/glossary.md#kubo)) and as the decentralized network comprised of the individual [nodes](concepts/glossary.md#node) that are running protocol implementations.
 
 ## Get started
 
@@ -61,4 +63,4 @@ Are you looking for inspiration? You can find a huge collection of awesome commu
 
 IPFS has a bustling community of designers, developers, writers, and activists who are all helping to improve the project. You can join in by attending a local meetup, helping out at a conference, chatting online through [Discord](https://discord.com/invite/KKucsCpZmY), or joining a discussion in [the IPFS forum](https://discuss.ipfs.tech/).
 
-[Find out more in the Community section →](community/README.md)
+[Find out more in the Community section →](community/README.md)