La proprietà intellettuale resta protetta nel periodo di preavviso.

La is the definite article, meaning the.

So:

• la proprietà intellettuale = the intellectual property
• proprietà intellettuale = intellectual property in a more general or abstract sense

In this sentence, the speaker is referring to a specific thing or category already understood in context, so la is natural.

Also note that proprietà is a feminine noun, so the article is la.

Because it agrees with la proprietà, which is feminine singular.

In Italian, adjectives and past participles often agree in gender and number with the noun they describe.

Here:

• proprietà = feminine singular
• therefore protetto becomes protetta

Compare:

• il documento resta protetto = the document remains protected
• la proprietà resta protetta = the property remains protected

Resta is the third-person singular of restare, which here means remains or stays.

So:

• resta protetta = remains protected

This is very close to:

• rimane protetta

Both are possible in many contexts. Restare and rimanere often overlap in meaning when talking about a state continuing.

Because resta protetta emphasizes that the protected status continues.

So the idea is not just:

• is protected

but more specifically:

• remains protected
• continues to be protected

If the sentence were è protetta, it would simply state the condition.
With resta protetta, it suggests that this protection continues during that period.

You can think of it as a past participle used adjectivally.

The verb is:

• proteggere = to protect

Its past participle is:

• protetto / protetta / protetti / protette

In resta protetta, it functions like an adjective describing the state of la proprietà intellettuale.

So for a learner, the most useful understanding is:

• resta protetta = remains protected

Nel is a contraction of:

• in + il = nel

It usually means in the.

So:

• nel periodo = in the period
• or more naturally in English here, during the period

Italian often combines prepositions and articles this way:

• a + il = al
• di + il = del
• in + il = nel
• su + il = sul

Because periodo di preavviso means notice period or literally period of notice.

The full phrase is:

• nel periodo di preavviso = during the notice period

Using periodo makes the time frame explicit. In legal or formal language, this is very natural.

You may also see similar phrases like:

• durante il periodo di prova = during the probation period
• nel periodo contrattuale = during the contractual period

Preavviso means notice, especially advance notice given before something happens.

In job or contract contexts, it often means:

• notice period
• advance notice period
• period of notice before termination/resignation

So periodo di preavviso is a standard formal expression for the time between giving notice and the actual end of the contract or employment relationship.

Because di preavviso works like of notice in English.

In Italian, when one noun modifies another with di, the second noun often appears without an article, especially in fixed expressions.

So:

• periodo di preavviso = period of notice / notice period

This is similar to:

• contratto di lavoro = employment contract
• ufficio di polizia = police office/station
• diritto di proprietà = property right

Adding an article there would usually sound less natural or would change the nuance.

In Italian, most descriptive adjectives usually come after the noun.

So:

• proprietà intellettuale = intellectual property

This is the normal order.

English often puts adjectives before the noun, but Italian usually places them after:

• casa grande = big house
• diritto civile = civil law
• proprietà intellettuale = intellectual property

Here it is singular.

Proprietà is one of those Italian nouns ending in -à, and its form does not change between singular and plural.

So:

• la proprietà = the property
• le proprietà = the properties

The article tells you whether it is singular or plural.

In your sentence:

• la proprietà = singular

The accent shows that the stress falls on the last syllable:

• pro-prie-tà

Many Italian words stressed on the final syllable take a written accent, especially in standard spelling.

This is important both for pronunciation and spelling.

Yes. La proprietà intellettuale rimane protetta nel periodo di preavviso is also correct.

Both resta and rimane can mean remains.

Very roughly:

• resta can feel slightly more concise or formal in certain contexts
• rimane is also very common and natural

In a formal/legal sentence like this, either can work well.

Yes, you could say:

• La proprietà intellettuale resta protetta durante il periodo di preavviso.

This also means The intellectual property remains protected during the notice period.

Both are natural.
Very often:

• nel periodo di... = in/during the period of...
• durante il periodo di... = during the period of...

Durante makes the time meaning a little more explicit, but the original sentence is perfectly normal.

Yes, it sounds formal and legal/contractual.

Clues include:

• proprietà intellettuale
• resta protetta
• periodo di preavviso

These are typical of contracts, policies, regulations, or HR/legal communication rather than everyday casual speech.

The structure is:

• La proprietà intellettuale = subject
• resta = verb
• protetta = complement describing the subject
• nel periodo di preavviso = time expression

So literally:

• The intellectual property remains protected in the notice period

More natural English:

• The intellectual property remains protected during the notice period.

A careful pronunciation would be approximately:

• La pro-prie-TÀ in-tel-let-TUA-le RE-sta pro-TET-ta nel pe-RIO-do di pre-av-VI-so.

A few points:

• proprietà has stress on the last syllable: -tà
• intellettuale has strong stress on -tua-
• protetta has stress on -tet-
• preavviso has stress on -vi-

Also, the double consonants matter in words like:

• intellettuale
• protetta
• preavviso does not have a double consonant, so it is lighter there

Usually it refers to the general concept or legal category of intellectual property, much like in English.

Depending on context, it may cover things like:

• copyrights
• patents
• trademarks
• trade secrets
• related rights

So even though proprietà is grammatically singular, the phrase often functions as a broad legal concept rather than referring to one single isolated item.