·11 min read
What is JWT? JSON Web Token Explained with Structure, Claims, and Security
Learn what JWT is, how JSON Web Tokens work, token structure, claims, signing algorithms, expiration, refresh tokens, and security best practices.
Read more →In-depth guides, tutorials, and explainers about web development tools, encoding, networking, security, and more.
Learn what JWT is, how JSON Web Tokens work, token structure, claims, signing algorithms, expiration, refresh tokens, and security best practices.
Read more →Learn what robots.txt is, how crawlers read it, syntax rules, allow/disallow directives, common mistakes, and best practices to avoid blocking important pages.
Read more →Learn what SQL is, how Structured Query Language works, SQL syntax for SELECT, INSERT, UPDATE, DELETE, JOINs, subqueries, indexing, transactions, SQL dialects (MySQL, PostgreSQL, SQLite, SQL Server), best practices, and common mistakes.
Read more →Learn what a calendar year is, how different calendar systems measure time, the history of the Gregorian calendar, how lunar vs solar vs lunisolar calendars work, Buddhist Era, Islamic Hijri, Hebrew, Persian, Chinese, Japanese, Ethiopian, and Indian Saka calendars explained.
Read more →Learn what BMI is, how Body Mass Index is calculated, BMI categories from underweight to obese, the history behind the formula, its limitations, ethnic variations, alternatives like waist-to-hip ratio, and when BMI matters for health.
Read more →Learn what WHOIS is, how domain registration lookup works, the WHOIS protocol history, WHOIS vs RDAP, how to read WHOIS records, EPP status codes, GDPR and privacy impact, domain lifecycle, and best practices for domain research.
Read more →Learn what Lorem Ipsum is, the history behind the world's most famous placeholder text, how it connects to Cicero's De Finibus, why designers use dummy text, Lorem Ipsum alternatives, and best practices.
Read more →Learn what UUIDs are, how universally unique identifiers work, UUID versions compared, collision probability, use cases in databases and distributed systems, UUID vs ULID vs Snowflake, and best practices.
Read more →Learn what hash functions are, how cryptographic hashing works, the properties that make hashes useful, MD5 vs SHA-1 vs SHA-256 vs SHA-512, collision attacks, password hashing with salts, HMAC, real-world applications in blockchain and digital signatures, and best practices.
Read more →Learn what barcodes are, how they encode data in patterns of bars and spaces, the history of the UPC, barcode symbologies (CODE128, CODE39, EAN-13, UPC), how barcode scanners work, check digits, GS1, and best practices for creating reliable barcodes.
Read more →Learn what QR codes are, how they encode data in a 2D matrix, the role of finder patterns and error correction, QR code versions and capacity, static vs dynamic codes, security considerations, and real-world applications.
Read more →Learn what Unix timestamps are, how Epoch time works, why January 1 1970 was chosen, the Year 2038 problem, seconds vs milliseconds, timezones, and how to work with timestamps in every programming language.
Read more →Learn what unit conversion is, how the metric and imperial systems work, conversion formulas for length, weight, temperature, volume, speed, and more — with practical examples and quick reference tables.
Read more →Learn what ZIP files are, how lossless compression works, DEFLATE and STORE methods, ZIP encryption (ZipCrypto vs AES-256), archive structure, ZIP64 extensions, and how to create and extract ZIP archives.
Read more →Learn what DNS leaks are, how they expose your browsing history even when using a VPN, how DNS resolution works, what causes DNS leaks, how to test for them, and how to fix and prevent DNS leaks.
Read more →Learn why websites go down, how uptime monitoring works, what HTTP status codes mean, how to check if a site is down for everyone or just you, common causes of downtime, and how to minimize outages.
Read more →Learn what SSL and TLS are, how HTTPS encryption works, what SSL certificates do, certificate types (DV, OV, EV), the TLS handshake, certificate chains, common errors, and how to check SSL certificates.
Read more →Learn what ping is, how ICMP echo requests work, what latency and packet loss mean, how to use the ping command, interpret results, troubleshoot network issues, and optimize your connection.
Read more →Learn what domain names are, how the domain name system is structured, TLD types (gTLD, ccTLD, new gTLDs), domain registration, WHOIS, domain age and its importance, domain expiration, transfers, and best practices.
Read more →Learn what IP addresses are, how IPv4 and IPv6 work, the difference between public and private IPs, static vs dynamic addresses, subnets, NAT, geolocation, and how to protect your IP.
Read more →Learn what DNS is, how domain name resolution works, the different DNS record types (A, AAAA, CNAME, MX, TXT, NS), DNS caching, propagation, security (DNSSEC), and common troubleshooting tips.
Read more →Learn what makes a password strong, how passwords get cracked, why length beats complexity, how password managers work, and best practices for staying secure online.
Read more →Learn about text case formats — camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and more. Understand naming conventions across programming languages and when to use each.
Read more →Learn what URL encoding (percent-encoding) is, how it works, which characters need encoding, and how to encode and decode URLs in JavaScript, Python, and more.
Read more →Learn how Roman numerals work, their seven symbols, the subtractive rule, how to read and write them, and where they're still used today.
Read more →Learn what number bases (radix systems) are, how positional notation works, and why binary, octal, decimal, and hexadecimal matter in computing.
Read more →Learn what octal (base-8) is, how it works, where it's used in computing — from Unix file permissions to programming literals — and how to convert between octal, decimal, and binary.
Read more →Learn what UTF-8 is, how it encodes every character on earth, why it dominates the web, and how it relates to ASCII and Unicode.
Read more →Learn what ASCII is, how it works, its full character table, and why it remains foundational to modern computing.
Read more →Learn what hexadecimal (hex) is, how it works, why developers use it, and how to convert between hex, decimal, and binary.
Read more →Learn what Base64 encoding is, how it works, why it exists, and when to use it. A practical guide with examples for developers.
Read more →Learn everything about JSON — what it is, how it works, its syntax rules, and why it became the most popular data format on the web.
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