What is the difference of credential-store and secret-key-credential-store

In the following table the different credential store implementations of different credential types are listed.

I still do not quite understand the difference of KeyStoreCredentialStore (credential-store) and PropertiesCredentialStore (secret-key-credential-store) in wildfly subsystem elytron. If KeyStoreCredentialStore supports SecretKeyCredential, why one need PropertiesCredentialStore type?

An official documentation describe the differences of credential store implementations with details very well. However, for someone starting new with this topic, it can be confusing. Hence, I thought of briefly describing the differences and practical benefits based on my experience:

KeyStoreCredentialStore (i.e. credential-store) and PropertiesCredentialStore (i.e. secret-key-credential-store) are two default credential store implementations WildFly Elytron contain.

1. KeyStoreCredentialStore implementation backed by a Java KeyStore which is protected using the mechanisms provided by the KeyStore implementations. As listed in table above it supports credential types as PasswordCredential, KeyPairCredential and SecretKeyCredential.

2. PropertiesCredentialStore is another implementation dedicated to store SecretKeyCredential using a properties file and its primary purpose is to provide an initial key to a server environment. It does not offer any protection of the credentials it stores but can be still from filesystem level its access restricted to just the application server process.

In my case I needed e.g. SecretKeyCredential to encrypt expression (i.e. passwords in clear text) in server configuration file and I added my SecretKey to KeyStoreCredentialStore protected by password, rather than using PropertiesCredentialStore.