in time i am concerned with my damn hard thesis , some bad questions arose in my brain 1- first as i know google is in america yeah. so www.google.com is managed from there also there exist www.google.de and www. google.com.tr so , if google is managed from america , how can .de and .com.tr be exist? 2-second one is about DNS for example while i connect to "www.hotmail.com" the mechanism is that i am able to enter these words not numbers is DNS but DNS is on TCP also UDP( both connection-oriented and connectionless) while i want to reach a site , isn't enough the dns server only in the network of the site i connect to? i mean IS IT A MUST THAT THE DNS SERVER exist in both client and server side? 3- third one is also related to DNS think you have a web site and your public ip address of web server was 220.127.116.11 and you decided to change your ISP for some specific reasons and clients were connecting to your site before , but your ip address would change because of moving to another ISP so , is this about DNS ? i think even without DNS , they could not connect to 18.104.22.168 anymore(because it changed so what is the thing DNS made here?