UX Glossary · E
End user
The person who actually uses the product, who is often not the person who bought it.
The end user is the person who operates the product to get something done. The qualifier “end” exists to distinguish them from everyone else in the chain: the buyer, the administrator, the integrator, the person who commissioned it.
Why the distinction is not pedantic
In consumer products, buyer and user are usually the same person, and their interests align. In enterprise and industrial products they are frequently different people with different incentives, and this is the single most common reason bad enterprise software survives.
The buyer evaluates a feature list, a price and a procurement process. The user lives with the interface for eight hours a day. Nothing in the purchase decision reliably transmits their experience, so a product can sell well and be resented by everyone who uses it.
What follows for research
Talking to the buyer tells you why it was purchased. Talking to the user tells you why it is worked around. Both matter, and only the second one tells you what to fix.
In safety-critical contexts the gap widens further, because the person exposed to the consequences of a poor interface may be neither the buyer nor the operator: a driver, a patient, a member of the public.
In practice
Ask early who signs, who administers, who operates and who is affected. If they are different people, the design has more than one audience and pretending otherwise is how enterprise products get their reputation.