Sales engineering is a hybrid of sales and engineering that exists in industrial and commercial markets. An engineering degree is not mandatory for a sales engineer, as long as they have sales knowledge and sufficient technical knowledge of the service or product they are called sales engineer. Buying decisions in these markets are made differently than those in many consumer contexts, being based more on technical information and rational analysis and less on style, fashion, or impulse. Therefore, selling in these markets cannot depend on consumer-type sales methods alone, and instead it relies heavily on technical information and problem-solving to convince buyers that they should spend money on the seller's products or services, in order to meet a business need (that is, to satisfy a business case). A sales engineer is thus both "a salesperson that understands and can apply engineering" and "an engineer that understands how to sell engineered systems". They thus not only sell but also provide advice and support. They provide this service to various internal or external customers, and they may work for a manufacturer (servicing its industrial-account/business-to-business customers), for a distributor (which in turn services the industrial-account/business-to-business customers), or for a third party such as an engineering consultancy or a systems integrator.

Sales engineers are a critical sales team member in many companies and industries around the world. They are more than just technical experts in their respective industries. Highly successful sales engineers must build and maintain parallel expertise in "soft skill" disciplines such as business acumen, presentation skills, building customer relationships, developing an engagement strategy, and having a thorough understanding of the targeted industry. Many companies have difficulty finding people who possess these qualities, plus have extensive technical knowledge.

The essence of the sales engineering role can be called by various names. Which name is most apt can even depend on which industry it is used in. Some common job titles that involve the essence of sales engineering include sales engineer, solutions engineer, solutions architect, systems engineer, customer engineer, pre-sales consultant, technical account manager, applications engineer or field applications engineer. The term systems engineering has various shades of meaning, however, as it is often more or less synonymous with industrial engineering; but in any market economy, industrial engineers will often end up providing some sales engineering as a necessary portion of their work. Service technicians in industrial fields may also find that their work challenges them to provide some sales engineering, to whatever extent they are capable of providing it, because they interface with customers having problems with equipment (or lacking the right equipment) and seeking solutions (anywhere from diagnosis and repair, to identifying entirely different systems that could be used instead).