Certificates have been an important part of securing communications for many years, but until recently, most server administrators only ever had to deal with the occasional SSL certificate to protect a website, Exchange, or SharePoint server. These SSL certificates are typically issued from a public certification authority, which meant that you did not need an on-premise public key infrastructure (PKI). In other words, I am still finding companies even today that do not have a Windows CA server in their environment, and are therefore unable to issue any certificates to their workstations, because they haven't needed to.
There are more and more technologies being released that require workstation or ...
