OEM usually starts from your approved design or sample; ODM involves development from a brief with agreed design responsibilities. Private-label work may add logos, labels, trims and packaging to an approved product specification.
For each route, confirm who supplies patterns and artwork, who owns approved files, how revisions are authorised and which processes are handled at the stated site or by specialist partners. Feasibility, minimums and schedule depend on the garment and should be confirmed in the written quotation. Compare the OEM and ODM service pages.