[ADD] inventory: What is the difference between warehouses and locations?

https://docs.google.com/document/d/184HMIFe9F0bOrLSZAT4bCUADM_K1DNcmtNGNEqQzC2c/edit#

inventory/settings/warehouses.rst

@@ -6,4 +6,6 @@ Warehouses
    :titlesonly:
    :glob:
 
-   warehouses/*
+   warehouses/difference_warehouse_location
+   warehouses/warehouse_creation
+   warehouses/location_creation

inventory/settings/warehouses/difference_warehouse_location.rst

@@ -1,3 +1,38 @@
 ========================================================
 What is the difference between warehouses and locations?
 ========================================================
+
+In Odoo, a **Warehouse** is the actual building/place in which your items
+are stocked. You can setup multiple warehouses and create moves between
+warehouses.
+
+A **Location**, is a specific space within your warehouse. It can be
+considered as a sublocation of your warehouse, as a shelf, a floor, an
+aisle, etc. Therefore, a location is part of one warehouse only and it
+is not possible to link one location to multiple warehouses. You can
+configure as much locations as you need under one warehouse.
+
+There are 3 types of locations:
+
+-   The **Physical Locations** are internal locations that are part of the
+    warehouses for which you are the owner. They can be the loading and
+    unloading area of your warehouse, a shelf or a department, etc.
+
+-   The **Partner Locations** are spaces within a customer and/or vendor’s
+    warehouse. They work the same way as Physical Locations with the only
+    difference being that you are not the owner of the warehouse.
+
+-   The **Virtual Locations** are places that do not exist, but in which
+    products can be placed when they are not physically in an inventory yet
+    (or anymore). They come in handy when you want to place lost products
+    out of your stock (in the **Inventory loss**), or when you want to take into
+    account products that are on their way to your warehouse (**Procurements**).
+
+In Odoo, locations are structured hierarchically. You can structure your
+locations as a tree, dependent on a parent-child relationship. This
+gives you more detailed levels of analysis of your stock operations and
+the organization of your warehouses.
+
+.. seealso::
+    * :doc:`warehouse_creation`
+    * :doc:`location_creation`

inventory/settings/warehouses/location_creation.rst

@@ -0,0 +1,3 @@
+=============================
+How to create a new location?
+=============================

inventory/settings/warehouses/warehouse_creation.rst

@@ -0,0 +1,3 @@
+==============================
+How to create a new warehouse?
+==============================