Заказчик запретил машинный перевод.

Заказчик is someone who places an order / commissions work. In many business, technical, and translation contexts, it often means the client who заказал работу.

Клиент is a more general word for customer/client.
So in this sentence, заказчик sounds especially natural if someone ordered a translation or another service.

• заказчик = commissioning party, person/company that ordered the work
• клиент = client/customer in a broader sense

Запретил is:

• past tense
• masculine singular
• from the verb запретить = to forbid / prohibit
• perfective

So it means forbade / prohibited as a completed action in the past.

The present/future pair is:

• запрещать = imperfective, to forbid / to be forbidding
• запретить = perfective, to forbid successfully / to impose a ban

Examples:

• Он запрещал это раньше. = He used to forbid this / was forbidding this earlier.
• Он запретил это. = He forbade it.

In the Russian past tense, the verb agrees with the subject in gender and number.

The subject here is заказчик, which is a masculine singular noun, so the verb is запретил.

Compare:

• Заказчик запретил... = masculine singular
• Заказчица запретила... = feminine singular
• Заказчики запретили... = plural

It is the direct object of запретил: the client prohibited machine translation.

Direct objects after this kind of verb normally go into the accusative case.

So машинный перевод is in the accusative.

Because перевод is a masculine inanimate noun.

For masculine inanimate nouns, the accusative singular is the same as the nominative singular.

So:

• nominative: машинный перевод
• accusative: машинный перевод

They look identical, but their role in the sentence is different.

Compare with an animate noun:

• Я вижу нового сотрудника. Here the accusative is different because сотрудник is animate.

The adjective must agree with the noun it describes.

The noun is перевод, which is:

• masculine
• singular
• here accusative, but for masculine inanimate it looks like nominative

So the adjective must also be masculine singular:

• машинный перевод

Compare:

• машинная система = feminine
• машинное обучение = neuter
• машинные переводы = plural

Yes. It is the normal Russian equivalent of machine translation.

Structure:

• машинный = machine / machine-based
• перевод = translation

Russian often uses an adjective + noun where English may use a noun + noun:

• машинный перевод = machine translation
• письменный перевод = written translation
• устный перевод = interpreting / oral translation

Not naturally.

Машинный перевод usually means machine translation as a process/method, or sometimes a translation produced by a machine depending on context. In this sentence, the most natural reading is:

The client prohibited the use of machine translation.

If you specifically wanted to talk about a particular machine-translated text, Russian would usually make that clearer, for example with extra wording.

Russian has no articles.

So Заказчик can mean:

• the client
• a client

and машинный перевод can mean:

• machine translation
• the machine translation (in some contexts)

You determine definiteness from context, not from articles.

In many isolated example sentences, English translations often use the client because it sounds natural.

Yes. Russian word order is relatively flexible, though the neutral order here is very natural:

• Заказчик запретил машинный перевод.

Other orders are possible, but they change emphasis:

• Машинный перевод запретил заказчик.
  = It was the client who prohibited machine translation.
• Запретил заказчик машинный перевод.
  = possible, but more marked or stylistic

For learners, the given order is the best neutral version.

Because it is a direct object.

The verb запретить can take a direct object without a preposition:

• запретить курение = to prohibit smoking
• запретить въезд = to prohibit entry
• запретить машинный перевод = to prohibit machine translation

Russian also has a pattern with запретить кому-то что-то:

• Заказчик запретил переводчику машинный перевод. = The client forbade the translator from using machine translation.

Here:

• переводчику = to the translator
• машинный перевод = what was forbidden

It can correspond to either, depending on context.

In this sentence, запретил most naturally means:

• forbade
• prohibited

If the context is a project or job, a very natural English rendering is:

• The client prohibited machine translation.
• The client forbade the use of machine translation.

The main word stresses are:

• зака́зчик
• запрети́л
• маши́нный
• перево́д

A rough pronunciation guide:

• зака́зчик ≈ za-KAZh-chik
• запрети́л ≈ za-prye-TEEL
• маши́нный ≈ ma-SHEEN-ny
• перево́д ≈ pye-rye-VOT

The doubled нн in машинный is spelled with two н, though in normal speech learners should focus more on the correct stress than on trying to over-pronounce the doubling.

Yes, sometimes.

• машинный перевод = the standard term for machine translation
• автоматический перевод = automatic translation

In modern usage, машинный перевод is usually the more standard and expected term, especially in translation and tech contexts. So the original sentence sounds very natural.