An original equipment manufacturer (OEM) traditionally is defined as a company whose goods are used as components in the products of another company, which then sells the finished item to users.

An EMS provider is now the term for a contract manufacturer in the electronics field that not only makes products for OEMs but also offers assistance with a wide array of value-added services, including: support with design, design for manufacture, supply chain management, configure-to-order, outbound logistics and repair elements.

EMS companies can be huge - in fact, they are multi-billion dollar businesses in their own right. So it’s not a surprise that they manufacture some of the world’s best-known products. For example, Microsoft's Xbox, Apple’s iPhone, HP printers, Cisco routers and a variety of products from companies like Sony and Nintendo are all believed to be built by Tier 1 EMS companies.

While these suppliers will often make "Top 10" lists, they specialise in manufacturing high volume, low complexity products and, as a result, demand multimillion-pound spend levels - which is why much of the world's consumer electronics end up shipping from their factories.

However, for OEMs that design and sell low to medium volume, often complex products, in sectors away from consumer electronics, Tier 1 suppliers may not be the most appropriate fit. Instead, OEMs are encouraged to take an alternative view of the EMS horizon, to find the most appropriate supplier for their business model and product range.

CEM stands for Contract Electronics Manufacturers.

ODM, or original design manufacturing, is also also referred to as “private labeling.” This is where an importer selects an already-existing product design from a factory catalog, makes a few small changes and sells it under their own brand name. Changes can include things like packaging or product bundles, colors and branding, and some limited adjustments to components or functionality.