برنامج المؤتمر عند مكتب التسجيل.

Because in Modern Standard Arabic, present-tense sentences like X is Y often do not use an explicit verb.

So:

• برنامج المؤتمر = the conference program
• عند مكتب التسجيل = at the registration desk

Together, they naturally mean:

• The conference program is at the registration desk.

This is called a nominal sentence in Arabic. In the present tense, Arabic usually leaves out is / are.

If you wanted a past tense, then Arabic would use a verb, for example:

• كان برنامج المؤتمر عند مكتب التسجيل = The conference program was at the registration desk.

This is because برنامج المؤتمر is an iḍāfa construction, often called a construct phrase.

In an iḍāfa:

• the first noun is the thing possessed or specified
• the second noun tells what it belongs to or what it is associated with

So:

• برنامج المؤتمر literally: program of the conference natural English: the conference program

Important rule:

• the first noun in an iḍāfa usually does not take الـ
• the whole phrase becomes definite if the second noun is definite

Here, المؤتمر has الـ, so the whole phrase برنامج المؤتمر is definite and means the conference program, not just a conference program.

المؤتمر is the second part of the iḍāfa: برنامج المؤتمر.

It tells you whose program it is or what program is meant:

• برنامج = program
• المؤتمر = the conference

So the relationship is:

• program of the conference
• or more naturally in English: the conference program

Grammatically, the second noun in an iḍāfa is in the genitive case.

With full case endings, this part would be read as:

• برنامجُ المؤتمرِ

So المؤتمرِ has a genitive ending because it follows an iḍāfa relationship.

Here, عند means something like:

• at
• by
• with
• near / in the possession of, depending on context

In this sentence, عند مكتب التسجيل means:

• at the registration desk
• or with the registration desk staff, depending on context

Why not في?

• في usually means in / inside
• عند often suggests at the place of or with

So:

• في مكتب التسجيل would sound more like in the registration office/desk area
• عند مكتب التسجيل sounds more like at the registration desk as a location or point of contact

In many real situations, عند is the more natural choice for something available at a counter or desk.

Yes.

• مكتب = office, desk
• التسجيل = registration

Together:

• مكتب التسجيل = registration desk / registration office
• literally: desk/office of registration

This is another iḍāfa, just like برنامج المؤتمر.

Again, the first noun:

• مكتب

does not take الـ, but the whole phrase can still be definite because the second noun:

• التسجيل

is definite.

So عند مكتب التسجيل means at the registration desk, not just at a registration desk, in normal usage.

The sentence is a nominal sentence made of:

1. برنامج المؤتمر — the topic of the sentence
2. عند مكتب التسجيل — the information being given about it

More traditionally:

• برنامج المؤتمر = mubtadaʾ (subject/topic)
• عند مكتب التسجيل = khabar (predicate/comment)

The predicate here is a prepositional/adverbial phrase telling location.

So the structure is:

• [The conference program] [at the registration desk]
• natural English: The conference program is at the registration desk.

With full case endings, it would be:

• بَرْنامَجُ المُؤْتَمَرِ عِندَ مَكْتَبِ التَّسْجِيلِ

A rough transliteration is:

• barnāmaju al-muʾtamari ʿinda maktabi at-tasjīli

A few notes:

• برنامجُ is nominative because it is the main noun of the sentence
• المؤتمرِ is genitive because it is the second noun in an iḍāfa
• عندَ is followed by a genitive noun
• مكتبِ is genitive after عند
• التسجيلِ is genitive because it is the second noun in another iḍāfa

In normal written Arabic, these short vowel endings are usually not written, so learners often see:

• برنامج المؤتمر عند مكتب التسجيل

It can mean either, depending on context.

مكتب commonly means:

• desk
• office

In a conference or event setting, مكتب التسجيل is often translated as:

• registration desk
• sometimes registration office

If the meaning already shown to the learner is registration desk, that is a very natural translation here.

So this is one of those nouns where the exact English word depends on the situation.

Yes, you could say:

• يوجد برنامج المؤتمر عند مكتب التسجيل

This would mean something like:

• The conference program is available at the registration desk
• or There is a conference program at the registration desk

But the original sentence:

• برنامج المؤتمر عند مكتب التسجيل

is shorter and very natural in Arabic, especially for signs, directions, or simple statements.

So:

• without يوجد = more direct and compact
• with يوجد = more explicit, often closer to there is

Arabic usually expresses this kind of noun relationship with iḍāfa.

English often puts one noun before another:

• conference program
• registration desk

Arabic instead usually links them as:

• برنامج المؤتمر = program of the conference
• مكتب التسجيل = desk/office of registration

This is one of the most important patterns in Arabic. It is extremely common and often corresponds to English noun-noun combinations.

So when English says:

• school bus
• city center
• conference schedule

Arabic often prefers an iḍāfa structure.

Yes. عند is a very flexible word.

It can mean:

• at
• with
• in the possession of
• sometimes even according to, depending on context

Examples:

• عندي كتاب = I have a book
  literally: At me is a book
• عند الطبيب = at the doctor’s
• عند العرب = according to the Arabs / among the Arabs

But in your sentence, the meaning is clearly locational:

• عند مكتب التسجيل = at the registration desk