Orev may be referring to Atlassian sunsetting their Server products. You now have either Cloud or Datacenter ($$$) as your only options.

On-premise for Jira, confluence, etc.

You can't self host now, just use their cloud offerings.

You can self-host, that’s the data center versions.

Upside, it’s the same code just difference license file, and it enables clustering (plus lots of other artificially limited features)

Downside, it’s a subscription license and it’s insanely expensive.