What is a client? Definition and meaning

A client in the world of business is a person, company, group or entity that buys goods or pays for services.

As opposed to customers, clients generally have an arrangement and a relationship with the seller.

For example, if someone buys a cup of coffee at a train station from a cafe stall, they are one of its customers. However, if the stall owner buys 35 kilograms of Colombian coffee from a supplier each month, he or she could be referred to as a client by the seller, especially if there are credit terms for paying invoices or some other business arrangement. The coffee stall could also be called the vendor’s customer in this case.

If you receive a service from a lawyer or another professional who gives advice, you are the client and never the customer, even if you only see that professional once and have no business arrangement. Psychologists commonly call their patients clients.


Client versus customerPeople spend time getting to know their client’s needs, and build a relationship. When a customer buys something in a shop, the clerk immediately focus on the next customer. The term customer can have the same meaning as client most of the time, but not the other way round – you could never say “The supermarket was full of clients,” but you can say “She is my best client,” or “She is my best customer,” with the same meaning.


According to the Financial Times Lexicon, a client is:

“Someone who pays for services or advice from a professional person or organization. Someone who buys something from a seller. A computer connected to another computer that controls it, for example in a network.”

Some linguists argue that the difference between a customer and client is that ‘customers simply buy something from others’, while ‘clients are under the protection of others’.

However, there are many examples that appear to break this explanation. The explanation is true when examining how customers and clients are treated. The video at the bottom of this page looks at this difference.

Companies that have their clients as the focus of their attention, rather than sales or the product, are called client-centric.

Client in computing

In computing, clients are either pieces of hardware or software that access a server’s service. The server is usually – but not always – on a different computer system, in such cases the client accesses the service through a network. the term applies to programs’ or devices’ role in the client-server model.

Client in computingWhen smartphones, tablets, laptops or desktop computers communicate with a server via a network – such as the Internet – they are the clients. A corporate network may consist of a client computer at each employee’s desk; they connect to a mainframe computer or central server that allows processing to be done on the client side rather than the server side, which reduce the processing requirements of the server. (Image: adapted from Wikipedia)

Servers and clients may be computer software run on the same machine and connect via inter-process communication techniques. The servers wait for clients to initiate connections that they may approve/accept.

The term was first used in computer jargon when referring to devices that weren’t capable of running their stand-alone programs, but were able to interact with remote computers through a network.

In ancient Rome, a client was a plebeian (commoner) who lived under the patronage of a patrician (nobleman, aristocrat).

Somebody who is receiving services, benefits, etc., from a government bureau or social welfare agency is sometimes referred to as a client.

Etymology of client

The word ‘client’ emerged in the English language in the fourteenth century, and came from Anglo-French clyent in the thirteen hundreds.

The Anglo-French terms originated from Latin clientem (nominative: cliens) meaning ‘follower, retainer’, which was perhaps a variant of cluere meaning ‘obey, follow, listen’. Some linguists say it is more likely to have come from clinare, which meant ‘to bend, incline’.

Client in other languages: cliente (Spanish, Portuguese, Italian); client (French); Klient (German); клиент (Russian); クライアント (Japanese); 客户 (Chinese), زبون (Arabic); klien (Indonesian); cliënt (Dutch); klient (Polish, Swedish, Danish, Norwegian).

Psychologist and clientIt is common for psychologists to refer to the people they treat as clients rather than patients.

Some idioms

While ‘client’ idioms are rare, those using the word ‘customer’ are very common. Here are a few:

An Ugly Customer: somebody who is likely to become angry and/or aggressive, even vicious. As in: “Be careful with Harry when he has been drinking, he can be an ugly customer. I’ve seen him punch people for no reason.”

Cool Customer: somebody who remains calm, even in very stressful situations.

Orson Welles client quoteOrson Welles (1915-1985), an American actor, director, writer and producer, once said: “As a producer, sitting on the other side of the desk, I have never once had an agent go out on a limb for his client and fight for him. I’ve never heard one say, ‘No, just a minute! This is the actor you should use.’ They will always say, ‘You don’t like him? I’ve got somebody else.’ They’re totally spineless.” (Image: orsonwelles.org)

An Awkward Customer: often it means a troublemaker, somebody who won’t behave in the way you’d expect or want them to.

The Customer is Always Right: a phrase used by most companies that sell goods or provide services. Employees are reminded of the idiom because happy customers are more likely to buy things and to come back for more.

A Tough Customer: somebody who is not easily satisfied; he or she is difficult to deal with. The idiom is often used when advising somebody not to approach, as in: “John is a tough customer. I’d stay away from him if I were you.”

Slippery Customer: refers to a person who is deceitful and also clever. It sometimes also includes people who are difficult to pin down – they are elusive.

Video – Difference between client and customer

In this Stampings is my Business video, the speaker explains what the difference is between clients and customers.