The short answer
A CRM manages the customer side — leads, follow-ups, deals and communication. An ERP manages the operations side — inventory, production, billing, service and HR.
Which to build first
If revenue is limited by missed follow-ups and unclear pipeline, start with CRM. If delivery is limited by stock errors, delayed billing and poor visibility, start with ERP. Many manufacturers start with an ERP that already includes a CRM module.
Why integration matters
When a won deal automatically becomes a project, order and invoice, teams stop re-entering data. Building both on a shared platform avoids the mismatch that comes with stitching separate products together.
Related service: CRM Software Development