Basically it means "to be" or "is". But their sentence structure is different so it's at the end of the sentence. Example それは猫です　Sore wa neko desu　　　That's a cat. 彼の名前はなんですか　Kare no namae wa nan desuka　What's his name? ケンです　　　　　　　Ken desu　　　　It's Ken Ather use of です is an auxiliary verb which is more polite way to express sentenses than "-だ” Example: これは車です。Kore wa kuruma desu　　It's a car これは車だ。　Kore wa kuruma da　　　It's a car It's also be used as a polite expression in adjective ending: 楽しいです　Tanoshii desu　　　I enjoy it/ It's fun It's not only for females but also for males. When people introduce themselves, they speak in polite way, therefore you can hear "desu" at the end of sentenses. Most commen sentenses for introducing yourself are: はじめまして　Hajime mashite Nice to meet you 私はXXXです　Watashi wa xxxdesu　My name is xxx 私は学生です　Watashi wa gakusei desu　　I am a student 私は３３歳です　Watashi wa 33sai desu　　　I am 33 years old 私は日本人です　Watashi wa nihonjin desu　　I am Japanese 私は東京出身です　Watashi wa tokyo shusshin desu　　I am from Tokyo よろしくお願いします　Yoroshiku onegai shimasu　　I hope to have a good relationship with you I hope it helped you a bit　　　：)　　Good luck！ 　

Desu is a copula. (a word used to link the subject of a sentence with a predicate) It shows that something is or isn't something else. It is one of the very few irregular forms in Japanese. Desu can act like the English "to be" (you know - is, am, are...) in the sense that desu is used to explain who or what something or someone is. It is also used when equating one thing with another. Let's take a look: ゾウは　大きい　です。 zou wa ookii desu. Elephants are large. [elephants-(topic particle)-big-are] これ　は　ねこ　 です 。 kore wa neko desu. This is a cat. [this-(topic particle)-cat-is]

Thankyou everybody that really helped :)

"Desu" has dozens of meaning, all of which you can only learn through steady study. One of its uses is to add it at the end of a sentence to make it sound formal. But there are other uses as well. Happy studying.

here you can learn more about " desu " http://en.wikibooks.org/wiki/Japanese/Existence_and_Copula Enjoy learning Japanese ^_^