Odoo is a suite of web based open source business apps.
The main Odoo Apps include an Open Source CRM, Website Builder, eCommerce, Warehouse Management, Project Management, Billing & Accounting, Point of Sale, Human Resources, Marketing, Manufacturing, ...
Odoo Apps can be used as stand-alone applications, but they also integrate seamlessly so you get a full-featured Open Source ERP when you install several Apps.
For a standard installation please follow the Setup instructions from the documentation.
To learn the software, we recommend the Odoo eLearning, or Scale-up, the business game. Developers can start with the developer tutorials