At the time of writing, Odoo's latest stable version is version 11, marked on GitHub as branch 11.0. This is the version we will work with throughout the book.
It's important to note that Odoo databases are incompatible between Odoo major versions. This means that if you run an Odoo 11 server against a database created for a previous major version of Odoo, it won't work. Non-trivial migration work is needed before a database can be used with a later version of the product.
The same is true for addon modules: as a general rule, an addon module developed for an Odoo major version will not work with other versions. When downloading a community module from the web, make sure it targets the Odoo version you are using.
On the other hand, major releases (10.0, 11.0) are expected to receive frequent updates, but these should be mostly...
