What is Odoo? – Open Source ERP & Business Platform

What is an ERP?

ERP stands for Enterprise Resource Planning — software that integrates core business processes into one unified system. Before ERP, companies used separate, disconnected tools: one app for accounting, another for inventory, another for sales. These tools rarely talked to each other, leading to duplicate data, manual reconciliation, and constant errors.

Odoo's approach is modular: you install only the modules you need. Each module handles one business area, and all modules share the same database, user system, and UI framework.

Odoo as a Development Framework

Odoo is not just an ERP — it's a Python web framework. It has four distinct layers that work together to power every module:

• Python ORM — Models are Python classes. The ORM handles all SQL automatically.
• XML Views — UI is defined in XML files that Odoo stores and renders.
• OWL JS Frontend — The browser client is built on Odoo's own JavaScript framework, OWL.
• PostgreSQL Database — Every model maps to a PostgreSQL table.

Here is a minimal Odoo model — the foundational building block of every custom module:

from odoo import models, fields

class Book(models.Model):
    _name = 'library.book'
    _description = 'Library Book'

    name = fields.Char(string='Title', required=True)
    author_id = fields.Many2one('res.partner', string='Author')
    price = fields.Float(string='Price')
    active = fields.Boolean(default=True)

The ORM handles CREATE TABLE, SELECT, JOIN, UPDATE, and DELETE automatically based on the model definition. You never write raw SQL for standard CRUD operations.

Community vs Enterprise

Odoo comes in two editions. As a developer, the important thing to know is that both editions use the same API — Enterprise just adds more modules on top of the same framework.

Community edition is free, open-source (LGPL), and hosted publicly on GitHub. Enterprise edition is paid, adds proprietary modules (advanced accounting, payroll, IoT, mobile), but uses the same Python/ORM/XML framework underneath. For learning Odoo development, Community edition is all you need.

Odoo Versions

Odoo follows an annual release cycle. Major versions are not backward compatible — a module written for Odoo 16 needs migration work to run on Odoo 17. Long-term stable releases are versions 14, 16, and 17.