With the server option, your application runs on a single server. The server will eventually reach its performance limit with more users. The application will slow down, decreasing the productivity of your teams. Should the server or database completely fail, your teams will no longer have access.
Data Center Architecture
With the data center option, your applications run simultaneously on several servers. Requests are simply distributed with the help of a load balancer should the number of users increases. Thanks to the data center architecture, the systems remain available in the case of failures because there are other servers available to process the requests.
Server or Data Center: an in-depth comparison
Scaling & Performance
Reliability & Stability
Strategy & Benefits
All deployment variants at a glance
Atlassian Data Center