![[LMG S4] Issue 50: Complex file formats and the Document](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue050/issue050_01.png)
[LMG S4] Issue 50: Complex file formats and the Document
Previously: A file consists of data, preceded by a file header which describes the data. Software (including operating systems) detect the kind of data...
![[LMG S4] Issue 49: What is a File?](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue049/issue049_01.png)
[LMG S4] Issue 49: What is a File?
Previously: A video container can hold one or more audio, video, or text data streams. To encode or decode a data stream, you need to have the necessary...
![[LMG S4] Issue 48: Of containers and codecs](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue048/issue048_01.png)
[LMG S4] Issue 48: Of containers and codecs
Previously: Data cannot be compressed beyond its predictability limit in a lossless fashion. Lossless compression does not discard any information. It spots...
![[LMG S4] Issue 47: Lossless compression](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue047/issue047_01.png)
[LMG S4] Issue 47: Lossless compression
Previously: Computers compress image and audio data through a process similar to summarising: it analyses the data using algorithms that use brightness and...
![[LMG S4] Issue 46: Lossy compression](https://github.com/ngjunsiang/laymansguide/blob/release/season4/issue046/issue046_01.jpg?raw=true)
[LMG S4] Issue 46: Lossy compression
Previously: Humans can distinguish 120 dB of loudness, which means the loudest perceivable sound is a million times louder than the softest perceivable...
![[LMG S4] Issue 45: Audio, a sampling of values](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue045/issue045_01.png)
[LMG S4] Issue 45: Audio, a sampling of values
Previously: An image’s resolution describes its dimensions. Its pixel resolution gives an indication of its physical size (if printed or displayed on a...
[LMG S4] Issue 44: Image resolution
Previously: Colour is stored as a combination of red, green, and blue. In a computer system, each colour is stored as one byte (8 bits), allowing for 256...
![[LMG S4] Issue 43: Images, a mosaic of 3 colours](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season4/issue043/issue043_01.png)
[LMG S4] Issue 43: Images, a mosaic of 3 colours
Previously: Unicode is an encoding format which is meant to support every language, ever. Most websites, apps, and interfaces support it today. In the last...
TYPO for [LMG S4] Issue 42: Unicode, computers go international
I made a typo this issue, right after the issue summary. It is below: But people need to know that it is not possible, and actually easy, to represent...
![[LMG S4] Issue 42: Unicode, computers go international](https://upload.wikimedia.org/wikipedia/commons/thumb/a/ac/Latin-1-infobox.svg/800px-Latin-1-infobox.svg.png)
[LMG S4] Issue 42: Unicode, computers go international
Previously: In ASCII encoding, text is stored as a 7-bit sequence. Text consists of letters, numbers, symbols, and control codes. Control codes instruct the...
![[LMG S4] Issue 41: ASCII, the typewriter digitised](https://github.com/ngjunsiang/laymansguide/blob/release/season4/issue041/issue041_01.jpg?raw=true)
[LMG S4] Issue 41: ASCII, the typewriter digitised
Previously: 8 bits comprise 1 byte. Humans count bytes in multiples of thousands, while computers count bytes in multiples of 1,024. It’s still difficult to...
[LMG S4] Issue 40: Bits and bytes
Previously: Networks enable data packets to get from one computer in the network to another through gateways that forward the data packets according to fixed...
![[LMG S3] Issue 39: Caches and caching](https://github.com/ngjunsiang/laymansguide/blob/release/season3/issue039/issue039_01.jpg?raw=true)
[LMG S3] Issue 39: Caches and caching
Previously: When a webpage document loads (Stage 1), it is processed by the web browser, which then loads other requested resources, such as stylesheets,...
![[LMG S3] Issue 38: Loading a web page](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season3/issue038/issue038_01.png)
[LMG S3] Issue 38: Loading a web page
Previously: Data packets hop from server to server. The more hops a packet must undergo, the longer the latency. The slower the servers along the route, the...
![[LMG S3] Issue 37: Traceroute–Google Maps for data packets](https://raw.githubusercontent.com/ngjunsiang/laymansguide/release/season3/issue037/issue037_01.png)
[LMG S3] Issue 37: Traceroute–Google Maps for data packets
Previously: Latency is the time duration between a ping packet being sent out and its response being received. It is an indication of how far away a target...
[LMG S3] Issue 36: Latency
Previously: VPNs link devices that are not within the same network using an encrypted tunnel that prevents gateways from snooping on the data packet as it...
[LMG S3] Issue 35: Virtual Private Networks (VPNs)
Previously: Firewalls block data packets that match certain rules. They decrypt the data packet layer by layer, dropping those that match its programmed...
[LMG S3] Issue 34: Firewalls
Previously: Data is encapsulated when it goes out from an app onto the internet as a request or response. First, in the TCP layer, the OS tags the request...
[LMG S3] Issue 33: Port numbers
Previously: The devices on your home network share the single ISP-assigned IP address through your router. The router rewrites the source IP and port number...
![[LMG S3] Issue 32: Sharing a public IP address: Network Address Traversal](https://github.com/ngjunsiang/laymansguide/blob/master/season1/issue008/issue008_01.png?raw=true)
[LMG S3] Issue 32: Sharing a public IP address: Network Address Traversal
Previously: A router assigns IP addresses automatically using DHCP. It reserves any registered static IP addresses for devices identified by their MAC...