When we try to find a website, we typically do it in two ways, 1) type in the Universal Resources Locator in the toolbar directly, 2) go to google and search for the domain name (YouTube, Amazon, etc.)
Based on the readings and video introductions for this week, the two ways of opening webpages are essentially sending request to the server and then get feedback. The URLs are displayed in a hierarchical fashion. For instance, if I try to locate the official website of Amazon, “http” stands for the language used for computers to interpret and communicate, but I realized I did not have to specifically type that in to locate the correct website. That is because the browser makes assumptions based on the port number, which has its own assigned task and is associated with IP address and protocol type of communication. As we can see from the table below, port number 80 is in charge of the Hypertext Transfer Protocol in WWW. If we do not type in http://, the browser automatically assumes 80 as it is the standard port for HTTP, thus directs us to the correct page.
The DNS holds responsible for our request for a certain website. If we input “amazon.com”, our computer communicates to the server asking the address of the website. If the server has not heard of this, it forwards the request to the domain name system“.com” asking for the server handling “amazon.com”. Once the address is found, the data returns in the form of HTML code and our computer receives them and reassembles them, therefore appears the graphic interface of website or application on our screen. Because of the existence of DNS, although we do not always have to put in “http”, we do need to get the domain name right. No IP address of “amazon.gov” will be found because there is no amazon under the governance of “.gov”-unless they create one in the future.
HTML coding controls how a webpage appears to users, where the images are placed, how wide is the frame, etc. The text is contained as part of the coding, but other files like videos and images come with their own URLs. Every piece of information is transmitted through the internet in data packets, our computer reconstructs the information when they are received. In this fault-tolerable process, the packets do not have to follow the same path and arrive at the exact same time. But the images and videos are retrieved in a slower manner, especially when they contain larger bits of data and the network is congested. This explains why sometimes when we open a page, we can see the text but the images are still loading.