#IT Knowledge
63 posts
What Is an SSL Certificate, and Why Do You Need One? Certificates and the Trust Chain of a CA
What an SSL certificate is, why you need one, and who vouches for it — explained without code. It covers the certificate authority (CA) and the trust chain from root to intermediate to site certificate, and why a warning appears when a certificate expires, at a concept level.
What Is a Domain, and Why Do You Need One? Nameservers and DNS Records
What a domain is, why you need a name when you already have an IP address, and what the nameservers and DNS records that make that name actually work are — explained at a concept level, without code. The hands-on setup is covered in a separate practical post.
How Are Online Payments Processed? Payment Gateways, Authorization, and Settlement Made Simple
This post explains, without any code, what happens in the few seconds after you press the pay button in online shopping. It covers what a payment gateway does, the difference between authorization and settlement, and who actually holds your card information, all at a non-developer's level.
How Does "Sign in with Google" Work? OAuth Made Simple
This post explains, without any code, whether a service learns your password when you log in with Google, and how social login works. It covers the principle of not handing over your password, OAuth and the consent screen, and the information received via a token, at a non-developer's level.
How Do Push Notifications Reach My Phone? Push Tokens and the Delivery Flow
This post explains, without any code, how a push notification reaches exactly your phone. It covers why the app doesn't send directly but goes through Apple's and Google's push servers, how a push token works as an address, and when permissions and tokens change, at a non-developer's level.
How Does Video Streaming Play Without Buffering? The Basics of Streaming and Codecs
This post explains, without any code, how video plays without buffering. It covers streaming that receives video in chunks, codecs that shrink heavy video, adaptive streaming that changes quality to match the network, and CDNs, at a non-developer's level.
How Are QR Codes and Barcodes Read? The Basics of Encoding
This post explains, without any code, how barcodes and QR codes hold information and get read by machines. It covers the numbers held in stripes and dots, clears up the misconception that a QR code holds the full content rather than just an address, and error correction, at a non-developer's level.
How Does Google Search Work? The Basics of Crawling, Indexing, and Ranking
This post explains, without any code, how Google returns millions of sorted results in under a second. It walks through the three stages — gathering pages by crawling, organizing them into an index, and deciding their order by ranking — at a non-developer's level.
How Do Chatbots Answer? The Difference Between Rule-Based and AI Chatbots
This post explains, without any code, how a support chatbot produces its answers. It covers the difference between rule-based chatbots that follow a fixed path and AI chatbots that understand sentences, how the two are mixed in practice, and the limit of hallucination, at a non-developer's level.
Why Are There So Many Image File Types? The Basics of JPG, PNG, and Compression
This post explains, without any code, why there are so many image formats, what the compression beneath them is, and which format to choose when. It covers pixels and numbers, lossless and lossy compression, and the differences between JPG, PNG, and WebP, at a non-developer's level.
How Maps and Your Location Are Displayed: GPS, Geocoding, and Map APIs
This post explains, without any code, how a map app finds your location and how addresses and maps connect. It covers GPS and supporting signals, the geocoding that links addresses and coordinates, map APIs, and location as sensitive personal data, at a non-developer's level.
How Apps and the Web Differ — Native, Web Apps, and App Store Review
A code-free explanation of how native apps, the web, and hybrid apps differ — and why an app requires installation and store review while the web opens with just an address.