There are two styles of technical Korean writing and these are primarily expressed in sentence endings.
In terms of the language as a whole, this is a simplification, since there are any number of local dialects that complicate things, written endings that can also be used in spoken language to add formality, written endings to show informality, endings that can be switched out in spoken language to show affection or relative status, and even a whole other antiquated style (i.e. "Shakespearean" Korean) used today only to address God.
But from a practical standpoint, in the technical translations that we deliver in Korean, unless quoting spoken speech, we only use two styles. Furthermore, since standard Korean sentences always end in a verb, this means nearly every complete sentence in formal written Korean uses one of the two sets of endings.
The following is a simple table showing these endings. For the sake of simplicity, I've removed all the nuances you'll find in a Korean grammar book and just stripped it to the basics.
Sentence Endings in Formal Styles of Written Korean
Go ahead and take a look at a recent Korean translation your Korean translation team delivered to you. Do you see that every sentence ends in these characters?
(If you're seeing sentences ending in 요 or that don't have any of these endings, it means it's probably a spoken style.)
So when are these mainly used?
The personal form is most common in translations addressed to readers, such as marketing materials and official letters. The impersonal form is mainly used in writing without specific readers in mind, such as news articles, academic papers, software interfaces and legal contracts. In addition, the impersonal form is commonly applied to titles and bullet points within documents otherwise written in personal style.
There is room for flexibility here and so you may find variation from translator to translator. The key point though is consistency. In most cases, a translator should use the same style throughout a document.
Korean Translation Tip – A good translator will use styles correctly and consistently. This doesn't mean a client reviewer won't occasionally ask to change. As long as your translator has been consistent with one or the other style above and can provide a proper rationale for that decision in line with my guidelines, the use of styles in the translation is probably correct.
BTW, this fancy and complicated system of styles is nearly completely lost in translations from Korean to English. We have ways in English to express levels of formality and closeness (e.g. "Hey John!", "Dear Mr. Smith", "Yo!", "To whom it may concern:", etc.) but the rules aren't as systematized as in Korean and the differences must often be left out when translating to English. Otherwise, you'll get awkward translations as described in my previous My Esteemed Translation Client Reader tip.