What is the difference between Media and MediaTemplate in WIX?

Is there are manual cabinet file's preparing VS automatic cabinet file's creation during building wix project?

Or may be this is something else ?

What is product Wxs?

Product. wxs is the source file of your setup project. A newly created project contains the XML code shown below.

How do you create a WIX file?

Click File, then click New, then click Project. Name your project "MySetup" and press OK. In the MySetup project, right-click on the References node and choose Add Reference.... Navigate to the Projects tab, click on the MyApplication project, and click the Add button, and then press OK.

MediaTemplate replaced Media and is available starting in WiX 3.8. Take a read at:

WiX and cabinetry

Basically the Media element took a lot of code to describe what to do when you had more then 1 CAB file. The MediaTemplate element is syntactical sugar that reduces this to one line.

Many smaller installers with just 1 CAB won't care one way or the other. But when you start to build large MSIs it'll help.