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EnglandComputer Science

1.3 Exchanging data

4 dot points across 4 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How are web pages built from HTML, CSS and JavaScript, and how do search engines rank them?

Web technologies: HTML for structure, CSS for presentation and JavaScript for client-side behaviour, the difference between client-side and server-side processing, and how search engines index and rank pages using web crawlers and the PageRank algorithm.
An OCR H446 answer on web technologies: HTML for structure, CSS for presentation and JavaScript for client-side behaviour, the difference between client-side and server-side processing, and how search engines use web crawlers and the PageRank algorithm to index and rank pages.
13 min answer →

What hardware and protocols move a packet of data across a network, and what does each layer of the TCP/IP stack do?

Networks (LAN and WAN, network topologies, client-server and peer-to-peer), network hardware (NIC, switch, router, WAP), the need for protocols and protocol layering, the TCP/IP four-layer stack, and packet switching.
An OCR H446 answer on networks: LANs and WANs, topologies, client-server and peer-to-peer models, network hardware (NIC, switch, router, wireless access point), the need for protocols and layering, the TCP/IP four-layer stack, and packet switching.
14 min answer →

What threats face a network, and how do firewalls, proxies and encryption defend against them?

Network security: the threats from malware (viruses, worms, trojans), social engineering and network attacks, and the protective measures of firewalls, proxy servers, encryption and access control.
An OCR H446 answer on network security: the threats from malware (viruses, worms, trojans), social engineering such as phishing, and network attacks, together with the protective measures of firewalls, proxy servers, encryption and access control.
13 min answer →

How does the internet turn a web address you type into a connection to the right server?

The structure of the internet, the Domain Name System (DNS), URLs and IP and MAC addressing, the difference between the internet and the world wide web, and the protocols HTTP, HTTPS, FTP and the client-server model of the web.
An OCR H446 answer on the structure of the internet: the Domain Name System, URLs, IP and MAC addressing, the distinction between the internet and the world wide web, and the protocols HTTP, HTTPS and FTP within the client-server model of the web.
13 min answer →