Ten kod służy do autoryzacji.

Because kod is a masculine singular noun, and the demonstrative ten has to agree with it in gender, number, and case.

• ten = masculine singular
• ta = feminine singular
• to = neuter singular

So:

• ten kod = this code
• ta książka = this book
• to okno = this window

Here, kod is masculine, so ten is the correct form.

Kod is in the nominative singular.

That is because it is the subject of the sentence:

• Ten kod służy do autoryzacji.
• This code is used for authorization.

The verb służyć takes a subject in the nominative, so kod stays in its basic dictionary form here.

Służy is the 3rd person singular present tense of służyć.

So:

• służyć = to serve, to be used for, to function for
• służy = serves / is used for

In this sentence, służyć do is a very common pattern meaning:

• to be used for
• to serve for
• to function for

Examples:

• Ten nóż służy do krojenia chleba. = This knife is used for cutting bread.
• Aplikacja służy do zarządzania plikami. = The application is used for managing files.

Because służyć often combines with do + genitive to express purpose.

So the structure is:

• służyć do + noun
• służyć do + verbal noun

In this sentence:

• do autoryzacji = for authorization

This is one of the most common ways in Polish to say that something is intended for a particular function.

Compare:

• To urządzenie służy do pomiaru temperatury. = This device is used for measuring temperature.
• Ten przycisk służy do resetowania systemu. = This button is used for resetting the system.

Autoryzacji is in the genitive singular.

That is because the preposition do requires the genitive case.

The base form is:

• autoryzacja = authorization

After do, it becomes:

• do autoryzacji

This is a very common feminine noun pattern:

• informacja → do informacji
• rejestracja → do rejestracji
• autoryzacja → do autoryzacji

So the ending changes because Polish marks grammatical relationships through case endings.

It is a normal and widely used Polish word, especially in technical, administrative, and business contexts.

In IT, autoryzacja often means authorization, for example confirming permission or approving access. Depending on context, Polish may also use:

• uwierzytelnianie = authentication
• autentykacja = authentication (more technical/international)
• autoryzacja = authorization

In everyday tech Polish, people often use autoryzacja very naturally, especially when talking about codes, logins, banking, or security procedures.

You might hear something like that in casual speech, but Ten kod służy do autoryzacji is more natural and precise.

Why?

• służy do clearly expresses purpose/function
• jest do can sometimes sound more informal or less exact, depending on context

Compare:

• Ten kod służy do autoryzacji. = This code is used for authorization.
• To narzędzie służy do cięcia. = This tool is used for cutting.

Using służyć do is a very standard way to describe what something is for.

Because the subject is singular:

• ten kod = this code

So the verb must also be singular:

• Ten kod służy...

If the subject were plural, the verb would change:

• Te kody służą do autoryzacji. = These codes are used for authorization.

So:

• służy = singular
• służą = plural

Yes, Polish word order is fairly flexible, but the neutral, most natural order here is:

• Ten kod służy do autoryzacji.

You could change the order for emphasis, for example:

• Do autoryzacji służy ten kod.

This sounds more marked and emphasizes what the code is for.

In most normal contexts, especially for learners, the original order is the best one to use.

A rough pronunciation guide is:

• służy ≈ SWOO-zhi

More carefully:

• sł in Polish is pronounced roughly like sw
• u sounds like oo
• ż sounds like the s in measure
• y is a Polish vowel that does not exist exactly in English; it is a short central vowel

So służy sounds approximately like SWOO-zhih.

A very useful pattern is:

Ten/To/Ta + noun + służy do + genitive noun

Examples:

• Ten program służy do edycji zdjęć. = This program is used for editing photos.
• Ta funkcja służy do wyszukiwania danych. = This function is used for searching data.
• To narzędzie służy do naprawy. = This tool is used for repair.

So the key takeaway is:

• służyć do + genitive = to be used for / to serve for

If you learn that pattern, you can build many practical Polish sentences.