Transliteration is changing between transcription systems (two ways of writing the same thing). As above 'sawatdii', sawasdii, and 'สวัสดี' are all the same word, but they are transcribed differently using different alphabets and transcription systems. Transliteration is ther conversion between these different ways of writing the same thing.
In this section we'll explain the transcription system used by TypeThai. There are a variety of problems with existing transcription systems. They work generally well for reading (except Royal Thai), but not always well for writing, so we are working on an alternate system. Your input will be greatly appreciated! Let me know what works and doesn't work for you.