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Joe plays online games using the world wide web - Edexcel - GCSE Computer Science - Question 6 - 2020 - Paper 1
Question 6
Joe plays online games using the world wide web. (a) A sequence of processes is required to open a web page. Describe this sequence of processes. (b) The web page ... show full transcript
Worked Solution & Example Answer:Joe plays online games using the world wide web - Edexcel - GCSE Computer Science - Question 6 - 2020 - Paper 1
Step 1
A sequence of processes is required to open a web page.
Answer
To open a web page, several processes occur sequentially:
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User Input: The user enters a URL into the browser's address bar and hits Enter.
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DNS Resolution: The browser checks its cache for the IP address corresponding to the URL. If not found, it queries a DNS server to resolve the domain name to an IP address.
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TCP Connection: Once the IP address is obtained, the browser establishes a TCP connection to the server using the IP address, typically over port 80 for HTTP or port 443 for HTTPS.
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HTTP Request: The browser sends an HTTP request to the server for the webpage.
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Server Response: The server processes the request and sends back the requested webpage data (HTML, CSS, JavaScript).
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Rendering the Page: The browser receives the data, parses it, and renders it for display, loading additional resources like images and stylesheets as needed.
Step 2
Describe how a merge sort works.
Answer
Merge sort is a divide-and-conquer sorting algorithm that operates as follows:
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Divide: The list is split into two approximately equal halves until each sublist contains a single element.
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Conquer: The sublists are then merged back together in a sorted manner. This is done by comparing the smallest elements of the sublists and arranging them in order.
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Combine: This merging process is repeated until all sublists are combined into a single sorted list.
The time complexity of merge sort is O(n log n) in all cases (best, average, and worst) due to the consistent division of elements and the merging process.