用换行符/段落标记替换所有空格，形成单词列表

I am trying to vocab list for a Greek text we are translating in class. I want to replace every space or tab character with a paragraph mark so that every word appears on its own line. Can anyone give me the sed command, and explain what it is that I'm doing? I’m still trying to figure sed out.I am trying to vocab list for a Greek text we a