What is Windows
application streaming?

Older meanings of the phrase involved sending application files to a user's machine to run locally. Today it nearly always means streaming the display: the program never leaves the server, only its output does.

That has a useful side effect. Because the application and its files stay on the host, controlling what leaves is a matter of policy on the stream rather than locking down every endpoint.

It sits between a normal install and a full virtual desktop.

• Local install: fast and native, but you deploy and support it on every device.
• Virtual desktop (VDI): a whole managed desktop per user. Powerful, but heavier than many people need.
• Application streaming: just the app, in a browser, with a lot less to manage.

The main reasons are fewer installs, one place to update and secure the app, and access that is easy to grant and to take away. It also gives you somewhere to attach recording and data controls, because every session passes through the same point.

Streaming adds a network hop, so very latency-sensitive work feels different from a local app. The best test is to try your real application over your real connection. Heavy GPU applications may be better served by a full desktop.

The phrase has been used for a few different ideas. One sends an application's files to a user's machine as they are needed, so it can start before the whole thing has downloaded, and then runs locally. Another keeps the application on a server and sends only its display.

When people say application streaming today, they almost always mean the second one. It is simpler for the user, because nothing runs on their device, and simpler to secure, because the program and its data never leave the server.

Two streams cross the wire. One is the picture: what the application draws, sent as compressed image data, with unchanged areas left out. The other is input: mouse movement, clicks and key presses, sent back to the host.

Everything else, including the application's files, database connections and memory, stays on the host. That is why a stream is easier to govern than a local install.

These ideas overlap, and the words are often used loosely. Remote desktop connects you to a whole machine. VDI provides each user a managed virtual desktop. Application streaming publishes a single application.

In practice the line blurs. A platform can stream one app for most people and a full desktop for a few, from the same place. What matters is not the label but what you deliver, to whom, and what you can control.

It fits business software that has to stay on Windows: ERP and accounting clients, vendor tools, line-of-business apps, and anything you would rather not install on every device.

It fits less well where the application needs to be right next to the user's hardware, such as specialised peripherals, or where every millisecond of input latency counts. For GPU-heavy applications, a full desktop is often the better way to stream them.