The SSL certificate chain order consists of root certificates, intermediate certificates, and the end-user certificate. Root CAs are a trusted source of certificates. Intermediate CAs are bridges that link the end-user certificate to the root CA. An SSL certificate chain order is the list of intermediate CAs leading back to a trusted root CA.
As previously explained, an SSL certificate chain is the list of certificates that contains the SSL certificate, intermediate certificate authorities, and root certificate authority that enables the connecting device to verify that the SSL certificate is trustworthy. This SSL certificate chain begins with the SSL certificate and ends with the root certificate. All the intermediate certificates in between are links in the SSL certificate chain order.
In this chain, the intermediate certificate is the issuer of the SSL certificate and the root certificate is the issuer of the intermediate certificate. The intermediate certificate must be installed on the same server as the SSL certificate so that the connecting device (browsers, applications, mobile device, etc.) can trust it.
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