Ch 8 · The Web, Cyber-security & Digital Currency · Theory
Topic 8 of 10 in Networks & Data Transmission — How Machines Talk — 4 lessons.
The Internet vs the World Wide Web
Recall the distinction, because exams test it directly: the internet is the global network of connected computers (the hardware and connections); the World Wide Web is one *service* running on it — the pages and links you browse. When you open a page:
Cyber-security Threats
Networked systems face many threats — you must recognise each:
Protecting Against Threats
Matching protections: firewalls (filter traffic), encryption (unreadable if intercepted), strong passwords + two-factor authentication, anti-malware, user education (spotting phishing), and access rights. No single measure is enough — defence is layered.
Digital Currency & Blockchain
Digital currency exists only electronically (e.g. cryptocurrencies). The problem: without a bank, how do you stop someone spending the same coin twice? The answer is blockchain — a shared, public ledger of every transaction, stored across many computers.