What is JSON? Syntax, data types and common mistakes explained
JSON explained in plain language: syntax, the six data types, why APIs use it, the mistakes that break it, and how to read and validate JSON quickly.
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A growing library of practical explanations about technology, the internet, software and computers.
What is a webhook? How webhooks work, with examples and security tips
A webhook is an HTTP callback that notifies your app when an event happens. How webhooks differ from polling, how to verify signatures and handle retries.
Read the guide →API rate limits explained: why you get 429 and how to avoid it
How API rate limits work, what 429 Too Many Requests and Retry-After mean, common limiting algorithms, and how to build clients that stay within limits.
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HTTP status codes explained: 200, 301, 404, 429, 500 and more
What HTTP status codes mean, from 200 and 301 to 404, 429 and 502, how to see them in your browser, and how to fix the most common…
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Symmetric vs asymmetric encryption: what is the difference?
Symmetric encryption uses one shared key, public-key encryption uses a key pair. How each works, why HTTPS combines them, forward secrecy and post-quantum changes.
Read the guide →What are API services? Types, examples and how they work
API services explained: payments, maps, messaging, data, cloud and AI APIs, how integration works, pricing, and how to choose a reliable provider.
Read the guide →REST API methods: GET, POST, PUT, PATCH and DELETE explained
What each REST API method does, with request examples, status codes, PUT vs PATCH, and which requests are safe to retry.
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How do digital signatures work? A plain-language guide
A digital signature proves who signed a file and that it has not changed. How signing and verification work, how they differ from encryption and where you rely…
Read the guide →What is a REST API? Methods, status codes and examples
A REST API gives every piece of data its own URL and uses HTTP methods like GET and POST to read and change it. Requests, status codes, principles…
Read the guide →What is API access? API keys vs OAuth tokens explained
API access means proving who is calling and what they may do. How API keys and OAuth tokens work, when to use each, and how to keep them…
Read the guide →What is an SSH key? How SSH keys work and how to create one
How SSH key login works, how to create an Ed25519 key on Windows, macOS and Linux, add it to a server or GitHub, and fix Permission denied (publickey).
Read the guide →What is a public key? Public vs private keys explained simply
A public key is the shareable half of a key pair: it encrypts and verifies signatures, while the private key decrypts and signs. What it looks like, where…
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How to clear browser cache in Chrome, Edge, Firefox and Safari
Step-by-step instructions to clear the cache in every major browser on desktop and mobile, for all sites or just one, and when a hard reload is enough.
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Intel X520-DA1/DA2 firmware update with BootUtil (unsupported SFP+ module fix)
Intel X520 adapters (X520-DA1 with one SFP+ port, X520-DA2 with two) are among the most common 10 GbE cards in second-hand servers and home labs. They are cheap,…
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Why updates sometimes need a restart
Some updates replace files that a running process already loaded into memory. The old code can continue running until the process restarts, so the operating system schedules a…
Read the guide →How does public-key encryption work? Public and private keys explained
Public-key cryptography uses a related key pair. A public key can be shared with anyone; a private key must remain secret.
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Why two backups are better than one
A single backup can fail at the same time as the original through theft, fire, ransomware, account deletion or a simple storage error. Independent copies reduce the chance…
Read the guide →What is an API? How API access works, with examples
An API is an agreed way for one program to request data or an action from another. It defines endpoints, inputs, outputs, authentication and error behaviour.
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How email delivery works
Email moves through several systems. A sending client submits a message to a mail server, which looks up the recipient domain's mail records and transfers the message to…
Read the guide →Why file formats matter
A file format describes how information is arranged inside a file.
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How web pages become visible in a browser
Typing an address and seeing a page appear feels instantaneous, but a surprising amount happens in between.
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What CPU cores and threads mean
Processor specifications list cores, threads and clock speeds, and marketing tends to imply that bigger numbers always mean a faster computer.
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Why software needs permissions
Every time an app asks to use your camera, read your contacts or see your location, you are looking at a permission system at work.
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What browser private mode really changes
Private browsing, incognito mode, InPrivate: every major browser offers a mode that promises to leave fewer traces. It is genuinely useful, but its name and the dark colour…
Read the guide →How HTTPS certificates are checked
The padlock in the address bar is the visible result of a check that happens in a fraction of a second: the browser has confirmed that the server…
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What a browser extension can access
Browser extensions are small programs that run inside the browser and change how it behaves: blocking advertisements, filling passwords, translating text, saving articles.
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Why websites use responsive design
Open the same website on a phone, a tablet and a wide monitor and, if it is well built, you will see three different layouts of the same…
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How QR codes work and how to use them safely
QR codes went from a niche industrial tool to something printed on restaurant tables, parking meters, posters and payment terminals.
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Why backups fail when they are never restored
Almost everyone who has lost data had a backup of some kind. The backup existed; it simply did not work when needed.
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What open source means in practice
Most of the software running the internet, and a large part of what runs on your phone and laptop, is open source: its source code is published under…
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Cookies, sessions and why websites remember you
The web was designed without memory. Each request a browser sends is independent, and the server has no built-in way to know that the person asking for page…
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Cloud storage explained: sync, backup and sharing
Cloud storage is one of the most widely used and least understood services on the internet.
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How software updates are delivered safely
Software updates arrive so routinely that most people no longer think about what is happening: a program you already trust replaces parts of itself with code downloaded from…
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RAM, storage and why more memory is not always faster
"Add more memory" is the most common advice given to anyone with a slow computer, and it is right often enough to persist. It is also wrong often…
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How password managers reduce everyday risk
The advice to use a different strong password for every account is impossible to follow by memory, so most people compromise: a handful of passwords, reused with small…
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IP addresses, ports and the shape of a connectio
Every device that talks on a network needs an address so that replies can find their way back. On the internet that address is an IP address, and…
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How search engines discover and rank pages
A search engine answers a query in a fraction of a second, but almost none of that work happens when you type.
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What an operating system actually does
An operating system is the software that stands between hardware and every program you run.
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What Docker changes about running software
"It works on my machine" used to be the most expensive sentence in software.
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Two-factor authentication: why a second step matters
Passwords fail in predictable ways: they are guessed, reused across sites, leaked in breaches and typed into convincing fake login pages. Two-factor authentication (2FA) adds a second, independent…
Read the guide →HTTP and HTTPS: what changes when a site is secure
Every web page, image, form submission and API call travels over HTTP, the Hypertext Transfer Protocol. HTTPS is the same protocol carried inside an encrypted, authenticated tunnel.
Read the guide →What is browser cache? How it works and when to clear it
The second visit to a website is usually much faster than the first, and the reason is the browser cache: a store of previously downloaded files that the…
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SSD vs HDD: how to choose the right storage
Replacing a hard disk with a solid-state drive is the single upgrade that most changes how a computer feels: boot times drop from a minute to seconds, programs…
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VPN explained: what it protects and what it does not
A virtual private network is marketed as a switch that makes you anonymous, secure and invisible. It is none of those things.
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How DNS works when you open a website
Computers find each other by IP address, but people remember names. The Domain Name System is the distributed directory that turns versuss.space into an address a network can…
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