the hiragana writing for wa is わ the hiragana writing for ha is は ha is pronounced as wa when it is used as a particle. For example: English: i am ... (name) Japanese:わたしは…です。 Pronunciation: wa ta shi wa ...de su.

Is the other way around, sometimes ha is pronounced like wa, a common example of this is the greeting "konnichiwa", you write it こんにちは, the las syllable (は) being the hiragana for ha but you pronounce it wa in this case.