Depending on the intended use case, there are multiple ways to install Odoo - or not install it at all.
Online is the easiest way to use Odoo in production or to try it.
Packaged installers are suitable for testing Odoo and developing modules. They can be used for long-term production with additional deployment and maintenance work.
Source install provides greater flexibility, as it allows, for example, running multiple Odoo versions on the same system. It is adequate to develop modules and can be used as a base for production deployment.
A Docker base image is available for development or deployment.
There are two different editions.
Odoo Community is the free and open-source version of the software, licensed under the GNU LGPLv3. It is the core upon which Odoo Enterprise is built.
Odoo Enterprise is the shared source version of the software, giving access to more functionalities, including functional support, upgrades, and hosting. Pricing starts from one app free.
Switch from Community to Enterprise at any time (except for the source install).