Jedda is a city in Saudi Arabia on the Red Sea. It is the country’s biggest port: ships come in and out with goods, and many visitors fly in here too. Mecca, the holy city for Muslims, sits inland from it, so a lot of pilgrims pass through Jedda on the way. You will also see the spelling Jeddah, and that is the one most maps and news stories use now. Jedda is an older English spelling of the same place, not a different town. In English it is a proper name, so it takes a capital letter. People say “in Jedda” or “the port of Jedda,” not “a jedda.”

吉達（沙烏地阿拉伯紅海大港；今英文多寫 Jeddah）