![[LMG S6] Issue 70: The Cookie Factory](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season6/issue070/issue070_01.png)
[LMG S6] Issue 70: The Cookie Factory
Previously: Cookies are little fragments of information with a name and a value, and associated with a domain address. They are most commonly used to...
![[LMG S6] Issue 69: The Cookie Monster](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season6/issue069/issue069_01.png)
[LMG S6] Issue 69: The Cookie Monster
Previously: The old CPM model (cost per thousand impressions) in the early Internet was replaced by the CPC model (cost per click) after the dot-com bust....
[LMG S6] Issue 68: The Age of Bloat
Previously: Each click on a link, or even an ad, sends data to the server. This information can include an ID for the link you clicked, or the category of ad...
![[LMG S6] Issue 67: The Innocent Times](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season6/issue067/issue067_01.png)
[LMG S6] Issue 67: The Innocent Times
Previously: DoubleClick, the first commercially successfully ad server, launched in 1996. It ran a system that tracked the performance of banner ads across...
[LMG S6] Issue 66: Before the Cloud
Previously: Shared memory helps to reduce the amount of memory needed by all the applications running on an operating system. It also allows applications to...
![[LMG S5] Issue 65: Memory Sharing in the Operating System](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season5/issue065/issue065_01.png)
[LMG S5] Issue 65: Memory Sharing in the Operating System
Previously: Meltdown and Spectre require the programs executing them to have access to kernel memory space. Kernel address isolation attempts to prevent the...
[LMG S5] Issue 64: Fixing Meltdown and Spectre
Previously: For Meltdown and Spectre to work, they need two things: (1) Permission to carry out instructions (i.e. run programs) on the OS, and (2) knowledge...
[LMG S5] Issue 63: Limitations of Meltdown and Spectre
Previously: To snoop the cache, we: Flush the cache corresponding to the 256 memory addresses (to get a cache miss when attempting to load the data from...
[LMG S5] Issue 62: Cache snooping
Apologies for the delay in Issue 62, it took longer than expected to work out how to laymanise it enough to be easily understood. Much thanks to Alex for his...
[LMG S5] Issue 61: Mapping the cache
Previously: Speculative execution is a feature that lets the CPU speed up execution if it correctly predicts a decision point. The CPU carries out the...
[LMG S5] Issue 60: CPU Optimisation Part 2 – Speculative Execution and Spectre
Previously: A set of instructions can trick a CPU into reordering load instructions so that the data is temporarily loaded into the cache before the...
[LMG S5] Issue 59: Meltdown
Previously: The CPU comprises different types of execution units. All the execution units can run at the same time, but they may execute instructions over...
[LMG S5] Issue 58: CPU Optimisation Part 1 – Out-of-Order Processing
Previously: The CPU stores data for ready access in the CPU cache. Accessing data from the CPU cache is much faster than accessing data from main memory....
[LMG S5] Issue 57: Cache, the CPU’s working space
Previously: The operating system is responsible for listing and managing the computer’s resources, making them available to programs running on the computer,...
[LMG S5] Issue 56: Operating Systems and resource management
Previously: The CPU just executes instruction after instruction after instruction. Each instruction may consist of loading data from a memory location,...
[LMG S5] Issue 55: Addressing memory
Previously: To get useful output from a CPU, we must translate the operations we want it to perform into CPU instructions, in a process known as compiling....
[LMG S5] Issue 54: Compiling programming code into CPU instructions
Previously: CPUs are unconscious slaves that simply execute instruction after instruction, at a very fast rate. Last issue, I introduced the idea of the CPU...
[LMG S5] Issue 53: The CPU is an instruction-obeying slave
Previously: PDF’s markup language is more concerned with how things appear on the page than with what they were originally. Once the PDF is generated, it is...
[LMG S4] Issue 52: PDFs part 2 – Text and images
Previously: PDF is the gold standard for universal compatibility (supported by most software and platforms) and visual fidelity (displays exactly the same...
![[LMG S4] Issue 51: PDFs part 1 – Compatibility and fidelity](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue051/issue051_01.png)
[LMG S4] Issue 51: PDFs part 1 – Compatibility and fidelity
Previously: An HTML file contains markup tags that tell the browser how to interpret and format the text within the tags. Other document formats usually use...