Where is the deployment directory in Eclipse?

I'm developing a web app in Eclipse. where is the deployment directory tree situated? In the Apache directory structure or some sub-directory tree structure in my Java workspace tree? I ask because I went browsing the directory tree(s) when an update to my tutorial app didn't work and, assuming that the src subtree represents my development directory tree I was hoping that the WebContent/WEB-INF subtree would contain my deployment tree (I also assumed that when I run the app the deployment directory structure would be automatically created for me), but I found the WEB-INF empty.

I'm developing a web app in Eclipse. where is the deployment directory tree situated? In the Apache directory structure or some sub-directory tree structure in my Java workspace tree?

It all depends on how your Tomcat Server is configured. The default should be: .metadata/.plugins/org.eclipse.wst.server.core/tmp0. But you can change this in the Tomcat server configuration. To do so, go to the Servers view, double-click on your Tomcat server and modify the Server path and Deploy path:

I personally use the Tomcat installation for full control (and the default deploy path i.e. wtpwebapps).

If it is not possible to change something in the "Server Locations" section, then see this answer on how to change that.

Usually, Eclipse compiles into directories in the workspace. Once the build is complete, this directory is then copied by a deployment plugin into the directory Tomcat uses.

If you use the WTP plugin bundled in the Eclipse Java EE download, the deployment location is configurable in the server's property page within eclipse.