A. Using Citrix, you have a range of options for how applications are delivered to users. Among the many available, making the decision between two in particular can be difficult to the newbie XenApp administrator—published applications and streamed applications.

A published application has been installed on a Citrix XenApp server. Published applications run on the server, consume server resources, and only transfer screen updates and keyboard and mouse commands from the server to the client. Applications that must keep their execution in the datacenter or that have light resource needs are usually good candidates for being published.

On the other hand, some applications are needed when users can't connect to XenApp servers in the datacenter. Other applications use significant amounts of resources when they're used, making server installation a bad idea. When one big application consumes lots of resources, there simply aren't many left to share among other users. These applications make good candidates for streaming to user desktops, because streamed applications consume desktop resources and not server resources as they're used.

Things get less clear when applications are streamed directly to XenApp servers instead of to user desktops. With the features available in today's XenApp software, this can be a really useful practice. Remember that streamed applications install automatically without requiring extra effort at the console. Streamed applications can also be quickly removed, essentially just by deleting a few files. By streaming applications to your XenApp servers, they can be easily and automatically deployed as they're needed. Servers are also much more easily reconfigured to meet user demands.

In XenApp, these applications are published as "Streamed to a server." Once streamed, they're then published from that server as a published application.