A-Level Computer Science

22:30 Topic 1 Number Systems & Data This photo. This song. This very video. Your name, your messages, every file on every device — inside th… 23:48 Topic 2 Networks You tap send. In less than a second, your message leaps out of your phone, races across your city, dives… 22:38 Topic 3 Computers & Components Open up any computer — past the case, past the chips, all the way down to the silicon — and you find swi… 21:32 Topic 4 Von Neumann Architecture For most of history, a machine did one job. A loom wove cloth. A calculator added. To make it do somethi… 21:02 Topic 5 Operating Systems You have never seen it, and you never will — yet it is always there. Behind every app you open, every fi… 16:28 Topic 6 Security, Privacy & Integrity Right now, this very second, your devices are under attack. Not by a person hunched over a keyboard — by… 14:11 Topic 7 Ethics, Copyright & Licensing Imagine you build an A I tool that sorts job applications ten times faster. Your manager is delighted. B… 17:18 Topic 8 Databases & the Relational Model Before databases, each program kept its own flat files — one file per program. Picture a shop. The sales… 14:52 Topic 9 Computational Thinking Here is a task: build a system to run a whole shop's stock — every product, every sale, every delivery, … 17:40 Topic 10 Data Types & Structures Every value your program stores needs a data type — and picking the right one matters. Say you store whe… 24:05 Topic 11 Programming Basics A program must ask for a password, and keep asking until it is right. Simple — but which loop do you use… 19:27 Topic 12 The Program Development Life Cycle A tiny bug, if it slips through to release, can cost a fortune to fix — far more than catching it early.… 15:16 Topic 13 User-Defined Data Types A plain string field will happily store nonsense. Ask for a vehicle type, and someone types Bananas — th… 11:17 Topic 14 Why Protocols Are Needed Two computers want to talk, but one sends its data one way and the other expects it completely different… 15:02 Topic 15 RISC, Pipelines & Logic Two chip designers face the same problem: make programs run fast. One says — build powerful instructions… 14:07 Topic 16 Resources, Compilers & RPN Open a browser, a music player, and a game. You have one processor — maybe a few cores — yet all of them… 13:19 Topic 17 How Encryption Works Look at the padlock in your browser's address bar. You typed your bank's name, and somehow your laptop i… 13:12 Topic 18 What AI Is Nobody ever wrote the rules for telling a cat from a dog. No programmer sat down and typed "if it has po… 15:33 Topic 19 Searching & Sorting A phone book with a million names. If you check them one at a time, you might make a million comparisons… 13:52 Topic 20 Programming Paradigms Here is one job: list every student with an A grade. One programmer writes a loop — start at the first r…