This word is broader in meaning and usage than "tlumaczenie"; can be put in contexts other than linguistic, computer/software related for example. The "L" is a Polish letter right after the "regular L" in Polish alphabet.

przekład - literary translation, translation of written text
tłumaczenie - translation and/or interpreting

The first two words ("tłumaczenie" and "przekład") are most often used in a linguistic sense, but they can be used in other situations, as well. The third possibility "przsunięcie" is a mathematical term used in specific problems e.g "translations of axes", which means "przesunięcie osi"

Polish word przenoszenie is perhaps the most general equivalent of translation.
Przesuwanie is a term unsed in mathematics.
Konwersja is useful e.g. for currency translationin banking.
I am a computer man and I can not see any difference between linguistics and computer science concerning this word. However, computer people in Poland use the word translacja as a synonym of tłumaczenie.