Azure Key Vault helps solve the following problems:
Secrets Management: Azure Key Vault can be used to Securely store and tightly control access to tokens, passwords, certificates, API keys, and other secrets.
Key Management: Azure Key Vault can also be used as a Key Management solution. Azure Key Vault makes it easy to create and control the encryption keys used to encrypt your data.
Certificate Management: Azure Key Vault is also a service that lets you easily provision, manage, and deploy public and private Secure Sockets Layer/Transport Layer Security (SSL/TLS) certificates for use with Azure and your internal connected resources.
Store secrets backed by Hardware Security Modules: The secrets and keys can be protected either by software or FIPS 140–2 Level 2 validates HSMs
Azure Key Vault has two service tiers: Standard, which encrypts with a software key, and a Premium tier, which includes HSM-protected keys.