Meaning – The term key ring, refers to a file that contains public keys, private keys, trusted roots, and certificates.
A keyring is a file that is necessary for Secure Sockets Layer (SSL) connection over the web. It is securely stored on the server which hosts the website. It contains the public/private key pair for the particular website. It also contains the public/private key pairs from various certificate authorities and the trusted root certificate for the various certification authorities.
Example of usage – “An entity or website administrator has to send a certificate signing request (CSR) to the CA. The CA then returns a signed certificate to the entity. This certificate received from the CA has to be stored in the keyring.”