Health Vault: What is this digital medical chart thing?

What is Health Vault? Check out:

• https://msdn.microsoft.com/en-us/healthvault/jj128027

Microsoft HealthVault Ecosystem Overview

• https://msdn.microsoft.com/en-us/healthvault/hh922966

Health Vault SDKs (.NET, Open Source)

• https://msdn.microsoft.com/en-us/healthvault/jj126730

Health Code Library:

• https://msdn.microsoft.com/en-us/healthvault/jj128428