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[Day 2]Who shows you the way to a website? -- IP Address, 'A' Record and 'CNAME' Record

Yesterday, we learned about the Domain and the 'MX' Record . With the 'guide',  'MX' Record of the Domain  'outlook.com', emails can be sent to the server. However, when you were learning how emails are sent with the 'MX' Record yesterday, did you wonder how you visit 'outlook.com' through a browser to write emails? Actually, besides the 'MX' Record which points to the address of the mail server, there is another Record called 'A' Record that tells where the website server is. For example, the 'A' Record of 'outlook.com' is '183.60.82.98'. (' 183.60.82.98 ' is an ' IP Address ', like the 'House Number' of the server.) So, when visiting 'outlook.com', the browser will first find the 'A' Record , ' 183.60.82.98 ', and then browse to this IP Address . Then, what's a  'CNAME' Record ? In fact, it's like a 'Shortcut'. For exampl

[Here we start] How is an email sent? -- Domain, Nameserver and 'MX' Record

This is the first tutorial of all. Here we start learning about a ' domain '. An email address looks like this: example@domain.com Suppose that you are example@gmail.com , writing an email to me, tzchz@hotmail.com .  When clicking the 'Send' button, h ave you ever thought about how it is sent? You may remember the description in the textbook when studying in school: When a user of Google Mail sends an email to a user of Microsoft Hotmail, Google's server will transport the mail to Microsoft's server, and then Microsoft delivers the mail to the receiver. When reading this, did you imagine that there must be something like a 'contract' between Google and Microsoft so that Google can transport the mail to Microsoft? In fact, mail servers are much easier to deploy, but there does be a 'contract'. It's called Domain Records .  The part after '@', ' hotmail.com' --  popularly called a 'URL', is a Domain ( Domain Name ). Eve