Transliteration, from the Latin trans, across, and littera, letter, is the practice of transferring a text from one writing system to another. Transliteration can be used to give people who can’t read other alphabets an idea how to pronounce words and names, though without some knowledge of the idiosyncrasies of pronunciation of the original languages, their pronunciation will probably sound only vaguely like the original.
In phrase books you often find transliterations designed to show how to pronounce things based on the mother tongues of the readers. Such guides tend to be confusing as the ‘phonetics’ might not make much sense to you. A few phrase books and language course provide IPA pronunciation guides, which are great, if you’re familiar with the IPA.
In the phrases section on Omniglot, I try to provide transliterations for all languages written with non-Latin writing systems. Many languages have several different transliteration systems and I usually choose the most widely-used. The transliterations may not make sense to everyone, but there are recordings of quite a few of the phrases, so you can at least hear how to pronounce them. Ideally there would be sound files for all the phrases, plus maybe IPA transcriptions, and with your help, maybe that will be the case one day.
I chose this word today because someone suggested that some of the transliterations on my phrases pages are confusing, especially to Americans. The trouble is, if I made the transliterations American-friendly, people from other countries might not find them useful.