Qbs' Building Application documentation lacks information for building from the command line

Finding the Qbs executable

Building Qbs apps from Qt Creator is easy, but eventually people need to know how to build from the command line (e.g. appveyor scripts for deployment, etc, etc).

http://doc.qt.io/qbs/building-applications.html says:

To build applications from the command line, enter the following commands:

cd examples/collidingmice
qbs

It doesn't say where the qbs executable is. Is it in qtbase/bin, is it in Creator's installation directory, or some other directory in my Qt installation?

What's a profile?

Next, I see:

The application is built using the default build profile that is set up in your Qbs configuration.

What is a profile? I checked http://doc.qt.io/qbs/cli-config.html (which was linked from the page) and saw http://doc.qt.io/qbs/qt-versions.html, which seems like something that should come before this in the steps of learning how to use Qbs, at least if you're building from the command line. So, a link to that page on the first mention of "profile" would be a good start.

However, I can't see any page that has an actual definition of a profile. What is it, why do I need it? These are things users will want to know.

Using existing profiles

As mentioned, I've used Qbs from within Creator, so I peeked around on the file system for profiles and found a bunch in /Users/mitch/.config/QtProject/qtcreator/qbs/1.12.0/profiles/:

qtc_Desktop__195bf052	qtc_Desktop__c2092895	qtc_qt5_10_f_f95f9657	qtc_qt5_dev__a45be53c
qtc_Desktop__1f2d618d	qtc_Desktop__dda5ca93	qtc_qt5_10_i_fb82ed9a	qtc_qt5_isle_ae72a3b3
qtc_Desktop__23fa2072	qtc_Desktop__de35868d	qtc_qt5_11_f_1c1c01b6	qtc_qt5_slat_558bc531
qtc_Desktop__3af7ef91	qtc_Desktop__f7465e7c	qtc_qt5_9_bi_3dbc429a
qtc_Desktop__7d4a8ee6	qtc_Qt_5_10__e0ce5600	qtc_qt5_9_fw_35224454
qtc_Desktop__7f4f2773	qtc_Qt_5_10__f95f9657	qtc_qt5_9_fw_c5983314

Creator is pretty much the authoritative source of which Qt versions I use on my machine, so it would be great if it was possible to reuse these profiles rather than having to create my own duplicated versions of them. If this is not possible, it would be great if the reason was explained in the documentation.