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…
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A growing library of practical explanations about technology, the internet, software and computers.
How public-key encryption works
Public-key cryptography uses a related key pair. A public key can be shared; a private key must remain secret. One common use is to encrypt data for a…
Read the guide →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 an API does
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 behavior. A mobile…
Read the guide →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 structured so another program can read it. Some formats are open and broadly documented; others depend on one application or vendor.…
Read the guide →How web pages become visible in a browser
A browser downloads HTML, builds a document structure, applies CSS, runs scripts and paints pixels to the screen. It may also reuse cached assets and schedule work across…
Read the guide →What CPU cores and threads mean
A CPU core is a physical processing unit. Modern processors can run several instruction streams at once through techniques such as simultaneous multithreading. More cores help with parallel…
Read the guide →Why software needs permissions
An application permission controls access to a resource such as the camera, contacts, location or files. Operating systems use permissions to reduce the damage a careless or compromised…
Read the guide →What browser private mode really changes
Private browsing usually prevents the browser from saving local history, form entries and some cookies after the window closes. It does not hide activity from the network provider,…
Read the guide →How HTTPS certificates are checked
A browser checks a website certificate to confirm that a trusted authority has linked a public key to the domain. The certificate does not make the site honest,…
Read the guide →What a browser extension can access
Browser extensions can add useful features by reading page content, changing requests or interacting with tabs. Their permissions describe the scope of that access, but a permission prompt…
Read the guide →Why websites use responsive design
Responsive design lets one website adapt its layout to different screens, input methods and orientations. CSS media queries, flexible grids and appropriately sized images help a page remain…
Read the guide →How QR codes work and how to use them safely
A QR code is a two-dimensional pattern that encodes data with error correction. A camera or scanner reads the modules, reconstructs the payload and presents an action such…
Read the guide →Why backups fail when they are never restored
A backup is only useful if it can be found, read and restored. Copying a file to another folder is not the same as designing recovery. Drives fail,…
Read the guide →What open source means in practice
Open-source software makes source code available under a license that grants specific rights to inspect, modify and redistribute it. The license matters: “open source” is not a promise…
Read the guide →Cookies, sessions and why websites remember you
A cookie is a small piece of data a website asks a browser to store and send back on later requests. Sites use cookies for preferences, login sessions,…
Read the guide →Cloud storage explained: sync, backup and sharing
Cloud storage usually means files are kept on remote servers and accessed over a network. Sync tools keep copies aligned across devices, while sharing tools give other people…
Read the guide →How software updates are delivered safely
An update replaces or adds software components to fix bugs, close security holes and introduce features. The system downloads a package, verifies its signature or integrity and applies…
Read the guide →RAM, storage and why more memory is not always faster
RAM is fast temporary working memory used by active programs. Storage keeps files when the device is off. When RAM fills up, an operating system may move less-used…
Read the guide →How password managers reduce everyday risk
A password manager generates and stores unique passwords so you do not have to reuse one secret across many services. The manager protects its vault with a master…
Read the guide →IP addresses, ports and the shape of a connection
An IP address identifies an interface on a network so packets can reach it. Private addresses work inside a local network, while public addresses are reachable through the…
Read the guide →How Wi-Fi works in a home network
Wi-Fi uses radio communication to connect devices to an access point, usually built into a home router. The router then connects that local network to the internet through…
Read the guide →How search engines discover and rank pages
Search engines generally work in three stages: crawling pages, indexing what they find and ranking results for a query. Crawlers follow links and read sitemaps, the index stores…
Read the guide →What an operating system actually does
An operating system coordinates hardware and gives applications common services. It schedules CPU time, manages memory, stores files, controls devices and enforces permissions. This lets a browser use…
Read the guide →What Docker changes about running software
Docker packages an application with a controlled user-space environment called a container. A container shares the host kernel but keeps the application’s files, processes and network settings separated…
Read the guide →Two-factor authentication: why a second step matters
Two-factor authentication requires two different categories of proof, such as something you know, something you have or something you are. A password plus a time-based code is stronger…
Read the guide →HTTP and HTTPS: what changes when a site is secure
HTTP is the protocol browsers use to request and receive web resources. HTTPS is HTTP carried through a TLS-encrypted connection. TLS helps prevent people on the network from…
Read the guide →How browser cache works and when to clear it
A browser cache stores reusable copies of files such as images, stylesheets and scripts. The next visit can load those files locally instead of downloading them again. Servers…
Read the guide →SSD vs HDD: how to choose the right storage
Solid-state drives store data in flash memory, while hard disk drives use spinning magnetic platters and a moving read head. The lack of moving parts makes an SSD…
Read the guide →VPN explained: what it protects and what it does not
A virtual private network creates an encrypted connection between your device and a VPN server. Your internet provider sees a connection to that server rather than every destination,…
Read the guide →How DNS works when you open a website
DNS is the directory system that turns a human-friendly domain name into an IP address a network can use. When you type a URL, your browser first checks…
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