Java KeyStore (JKS) is a proprietary type of keystore, a repository of security certificates, either authorization certificates or public key certificates, along with private keys used for various cryptographic purposes in a system. It's part of the Java Development Kit (JDK), widely used for storing private keys, and associated certificate chains that authenticate the corresponding public keys.

JKS files include a variety of digital certificates, including root, intermediate, and end-entity certificates. It uses a symmetric key to protect stored keys and certificates' integrity, making it an encrypted database that provides basic functionality for keys management.

JKS plays a vital role in the management and storage of digital certificates within a Java environment. It provides a secure method to store sensitive cryptographic keys and certificates on the filesystem, allowing for safe local storage and easy transport of keys and certificates for distribution.

Applications developed in Java, such as web servers or middleware, often use JKS for SSL/TLS implementations to establish secure connections. This ensures that the private keys and certificates required for these secure communications are readily available and stored in a secure manner.