When it comes to digital identity, each of us is defined through his own individual Identity. Moreover there exists one identity, which securely and privately stores all elements of my personal digital identity.
These are a few very interesting URLs that provide you with the basics to start your journey into Decentralized Identity.
ION - decentralized Layer 2 network for Decentralized Identifiers that runs atop the Bitcoin blockchain
Get started with Verifiable Credentials
Decentrilized Identity Foundation - Presentation specification
DI - Microsoft Whitepaper