edu is not a word you speak in a normal sentence. It is a short form of education, and it lives in internet addresses. When a web address ends in .edu, it usually belongs to a school, a college, or a university. In the United States, .edu is kept for real educational institutions. In Taiwan you will see .edu.tw on school and university websites — the .tw tells you it is Taiwan, and .edu tells you it is a place of learning. Though actually, you cannot buy a .edu address the way you buy a .com; it is meant to mark a school, not a shop. You read it as three letters, E-D-U, not as a spoken English word.