Potřeba informací je vysoká.

Because the noun potřeba (need) commonly takes a dependent noun in the genitive: potřeba čeho? = need of what?

So:

• potřeba informací = need for information
• literally, something like the need of information

This is very common in Czech. English often uses for, but Czech often uses a genitive noun instead.

That is a very natural question for English speakers.

In Czech, informace is often treated more like a countable noun than English information. So Czech commonly uses the plural where English would still use the uncountable singular:

• Potřeba informací je vysoká. = The need for information is high.

Using the plural here sounds normal and idiomatic in Czech.

A singular version can exist in some contexts, but it would usually sound more specific or stylistically different. In this sentence, informací is the most natural choice.

Because vysoká agrees with potřeba, which is a feminine singular noun.

Czech adjectives must agree with the noun they describe in:

• gender
• number
• case

Here:

• potřeba = feminine singular nominative
• so the adjective must also be feminine singular nominative: vysoká

Compare:

• vysoký = masculine
• vysoká = feminine
• vysoké = neuter / some plural forms

So je vysoká means is high, with the adjective matching potřeba.

Czech, like English, often uses high for abstract quantities, levels, or intensity.

So vysoká potřeba is similar to English high need or great need.

You may also hear velká potřeba, and it can work too, but:

• vysoká potřeba emphasizes a high level
• velká potřeba emphasizes great/strong need

In many contexts both are possible, but vysoká is perfectly natural here.

The subject is Potřeba informací.

The structure is:

• Potřeba informací = subject noun phrase
• je = is
• vysoká = predicate adjective

So the sentence literally works like:

• The need for information is high.

Even though informací is genitive, it is not the subject. The head noun of the subject is potřeba.

Here, potřeba is a noun meaning need.

That matters because Czech also has the expression:

• Je potřeba... = It is necessary... / There is a need to...

But your sentence is different:

• Potřeba informací je vysoká.

Here, potřeba is the thing being talked about. It is the subject of the sentence.

So compare:

• Je potřeba čekat. = It is necessary to wait.
• Potřeba informací je vysoká. = The need for information is high.

Same word, different structure.

Yes. Czech word order is fairly flexible because the endings show the grammatical relationships.

The neutral order here is:

• Potřeba informací je vysoká.

You could also say:

• Vysoká je potřeba informací.
• Je vysoká potřeba informací.

But those versions sound more marked and may shift emphasis.

For a learner, the basic sentence is the best default: Potřeba informací je vysoká.

Normally, in a regular full sentence, no.

Czech usually keeps the present-tense form of být (to be) in this kind of statement:

• Potřeba informací je vysoká.

If you remove je:

• Potřeba informací vysoká.

that sounds incomplete in standard everyday Czech, unless you are reading something very compressed like a headline, note, or stylistically elliptical text.

So for normal usage, keep je.

A rough pronunciation guide:

• Potřeba ≈ PO-trzhe-ba
• informací ≈ in-for-ma-TSEE
• je ≈ ye
• vysoká ≈ vi-so-KAA

A few useful notes:

• Czech stress is usually on the first syllable of each word.
• The ř in potřeba is a special Czech sound. English does not have it.
• The í in informací is a long vowel.

So the rhythm is roughly:

PO-tře-ba in-for-ma-cí je VY-so-ká

They are:

• potřeba = need
• informace = information / piece of information
• být = to be
• vysoký = high / tall

In the sentence, they appear as:

• potřeba → already in dictionary form
• informací → genitive plural of informace
• je → 3rd person singular of být
• vysoká → feminine singular form of vysoký

This is a good example of how Czech changes word endings to show grammar.