Odoo Modules Explained: Interactive Map of How Every Module Connects | Calibre
Odoo modules

Odoo Modules, Explained

Odoo isn't one program. It's a stack of apps (modules) that share one database. This map shows what each app does, how they connect, and the order to switch them on. Click any tile to trace its connections.

Modules or apps? Same thing

Odoo's marketing calls them Apps. Developers call them modules. Same thing: a self-contained package that adds one business function, like CRM, Inventory, or Accounting, and plugs straight into the shared database. The big user-facing ones show up as tiles you click. Smaller supporting modules install quietly underneath them.

These aren't separate programs that sync overnight. Every module reads and writes the same records. Enter a customer once and it's there in Sales, Invoicing, and Inventory at the same moment. Nothing to reconcile, nothing to re-type.

The interactive Odoo module map

Four layers, foundation at the bottom. Hover to trace how apps connect; click any app for a plain-English explanation of what it is, what it's built on, and what builds on it. Hit Play build order to watch it assemble bottom-up.

How Odoo Fits Together - and the order to build it

Every core app, stacked in four layers. You build from the foundation up: the engine first, then the nouns, then the operations, then your business model on top.

Build order
needs (built on)
extends (adds to)
record (data)
app (install & open)
engine (always on)
Hover or tap an app to light up its connections · click for the full breakdown & to jump between apps
Best explored on a larger screen. Click a tile to open its explanation.

How Odoo is structured: the four layers

Every module sits in one of four layers, and higher layers are built on the ones below. That's why you install from the foundation up.
Layer 1

The Platform

The always-on engine: the database, the screens, the messaging. You never install or choose it. Every Odoo has it, and the shared customer and vendor record lives here too.

Layer 2

The Nouns

The vocabulary of business: products, units, contacts, cost tags. Static data that just sits there. The operations above attach to it.

Layer 3

The Operations

What every business does: sell, buy, stock, bill, employ, run projects. Universal actions built on the records below. About half of all Odoo lives here.

Layer 4

Your Business Model

What makes it yours: eCommerce, POS, Manufacturing, Field Service, your country's tax rules. Optional. Add or remove freely.

The Odoo modules, by category

The core apps most businesses use. The ones we implement most often link to a full breakdown.

Sales & CRM

CRMLeads, pipeline, opportunities
SalesQuotations, orders, customer portal
SubscriptionsRecurring billing & renewals
RentalRent products out by the day/hour
Point of SaleIn-person register for shops & restaurants
AppointmentsOnline booking pages

Finance

InvoicingCustomer & vendor bills, taxes, the books
AccountingFull books: bank sync, reports, follow-ups
ExpensesEmployee expense claims
LocalizationsCountry tax & chart of accounts (CA, US...)

Inventory, Purchase & Manufacturing

InventoryWarehouses, stock moves, real-time valuation
PurchaseVendor orders, RFQs, reordering rules
ManufacturingProduction orders & bills of materials
QualityChecks & control points
MaintenanceEquipment upkeep & requests
ShippingCarrier connectors: UPS, FedEx, Canada Post

People (HR)

EmployeesCentral employee records
Time OffLeave requests & balances
RecruitmentJobs & applicant tracking
AttendancesClock in / clock out
PayrollPay calculation
PlanningShift scheduling

Services & Productivity

ProjectsTasks, milestones, planning
TimesheetsHours logged against work
Field ServiceOn-site jobs & dispatch
HelpdeskSupport tickets & SLAs
DocumentsFile management & sharing
SignSend documents for e-signature
KnowledgeInternal wiki & articles
SurveysQuestionnaires & forms

Website & Marketing

WebsiteDrag-and-drop site builder
eCommerceOnline store on your site
Email MarketingBulk campaigns
Marketing AutomationDrip journeys
EventsTicketing & event pages
eLearningCourses & training
Live ChatWebsite chat widget

Browse every Odoo app in detail →

Which Odoo modules does your business need?

A rough starting set by business type. The real answer depends on how you actually run things, which is what the scoping call is for.

Retail & eCommerce

  • Point of Sale
  • eCommerce + Website
  • Inventory + Purchase
  • Invoicing / Accounting
  • Email Marketing

Services & Agencies

  • CRM + Sales
  • Projects + Timesheets
  • Invoicing / Accounting
  • Helpdesk
  • Sign + Documents
Odoo for agencies →

Manufacturers

  • Manufacturing (MRP)
  • Inventory + Purchase
  • Quality + Maintenance
  • Sales + CRM
  • Accounting
Odoo for manufacturers →

Wholesale & Distribution

  • Inventory + Purchase
  • Sales + CRM
  • Accounting
  • Shipping connectors
  • Reordering rules
Odoo for distributors →

Odoo modules: frequently asked

What are Odoo modules?

Self-contained packages that each add one business function: CRM, Inventory, Accounting, Manufacturing, HR, and so on. You install only the ones you need, and they all read and write the same shared database. Enter something in one app and it shows up in the others with no re-entry.

Are Odoo apps and modules the same thing?

Yes. Odoo's marketing says "Apps"; developers say "modules." Both mean the same package that installs a business function and plugs into the shared database. "App" usually refers to the larger, user-facing ones shown as tiles; smaller supporting modules install quietly underneath them.

Do I have to install all of them?

No. Odoo is modular. You turn on only the apps you need and add more as you grow. The code for the rest sits dormant and doesn't clutter your database until you install it.

Do Odoo modules work together automatically?

Yes. Because every module reads the same records, they integrate by default instead of syncing. Install an app and Odoo pulls in the modules it depends on automatically, so the connections are wired up for you.

Which modules should I start with?

Usually the apps that match your core operation: CRM and Sales to win and process orders, Inventory if you hold stock, Accounting to keep the books. Then add Purchase, HR, Projects, Website, or Manufacturing as needed. The map above shows how they build on one another.

Are Odoo modules free?

The Community edition is free and open-source and includes the core apps. A few are Enterprise-only and need a paid plan: full Accounting, Studio, Marketing Automation, Field Service, and others. Many extra community modules are available free from the Odoo Community Association.

Not sure which modules you actually need?

We're an Odoo Certified Partner in Calgary. On a free scoping call, we map Odoo to how your business actually runs: which apps, in what order, and what it takes to go live without the mess.

Book your free scoping call →