什麼叫羅馬拼音?

Romanizaton by way of phonetic transcription.

From Wikipedia:
Romanization is the presentation of a word or language with the Roman ( Latin) alphabet, or a system for doing so, where the original word or language uses a different writing system. Each romanization has its own set of rules for pronunciation of the romanized words.

Examples of languages to which this process is often applied are Chinese, Japanese and Korean