What Is
Technology, clearly explained.
When learning development, familiar questions such as what open source is or why GitHub matters can be surprisingly hard to explain. Search results define the terms, but rarely connect why a concept emerged with how it is used in practice.
What Is turns widely searched technology topics into approachable guides. Each article walks through meaning, background, operation, real uses, and limitations so you can understand the documentation and conversations that follow.
Recent articles
Google AdSense vs. Google Ad Manager: What Is the Difference and How Should You Choose?
Compare Google AdSense and Google Ad Manager in terms of automation, direct sales, ad inventory control, demand competition, reporting, and operating costs, and learn which option fits different publisher scenarios.
Read moreWhen Is the Right Time to Adopt Redis?
An in-depth guide to deciding when to adopt Redis. Learn the fit criteria for caching, sessions, rate limiting, job queues, and real-time features; when to avoid Redis; and how to assess TTLs, invalidation, failures, security, and clustering.
Read moreWhat Do AI Competency Assessments Evaluate, and How Should You Prepare?
A systematic guide to what personality tests, strategy games, video interviews, and in-depth questions assess in AI competency assessments; company differences; fair preparation principles; and practical ways to improve performance.
Read moreWhen Should You Consider Adopting Apache Kafka?
Learn what Apache Kafka does, how it works, the signals that indicate it is a good fit, its limits around ordering, duplicates, and operations, how it differs from simple queues, and what to assess before adoption.
Read moreWhat Are Softmax and Cross-Entropy? Turning Logits into Probabilities and Training Loss
Learn what softmax and cross-entropy mean, how logits become probabilities and losses, the difference between multiclass and multilabel tasks, and how to implement them stably.
Read moreWhat Is Clean Code?
Explains the meaning and core characteristics of clean code; the roles of naming, structure, tests, and comments; differences from refactoring and coding style; and practical criteria for avoiding over-abstraction.
Read moreWhat Is AI Model Distillation, and How Do Small Models Learn From Large Ones?
Learn what AI model distillation, or knowledge distillation, means; how teacher and student models work; soft targets and temperature; output and feature distillation; how it differs from quantization and pruning; its benefits, limitations, and deployment checklist.
Read moreWhat Directory Conventions and Code Styles Do Codex and Claude Code Follow Well?
Learn the essentials of directory conventions and code style for Codex and Claude Code, including AGENTS.md, CLAUDE.md, scoped rules, validation commands, and shared operating practices.
Read moreWhat Is the Standard Next.js Project Directory Structure?
Learn why there is no single standard folder structure for Next.js projects and how to organize src, app, public, components, features, and lib around the App Router.
Read moreWhat Are the Advantages and Disadvantages of MySQL, and When Is It a Good Fit?
Learn the advantages and disadvantages of MySQL through InnoDB transactions, replication, high availability, indexes, partitioning, and query optimization, and determine when it is a suitable choice.
Read moreWhat Is the Difference Between LaTeX and KaTeX?
Compare the purpose, input and output, syntax compatibility, and use cases of LaTeX and KaTeX to choose the right tool for academic document typesetting or web math rendering.
Read moreWhat Are gzip and HTTP/3, and What Should You Improve First for Web Page Loading Performance?
Learn which layers gzip and HTTP/3 operate at, how they differ from HTTP/2 and Brotli, and under what conditions they have the greatest perceived effect on web page loading. This guide prioritizes performance improvements by scenario, including images, JavaScript, and TTFB.
Read moreFrequently asked questions (FAQ)
What kind of page is What Is?
What Is is a reading-focused collection that explains technology topics from the beginning, including their background, operation, uses, and limitations.
Can beginners read these guides?
Yes. The guides assume no prior use of a technology. Unfamiliar terms are introduced in context and the ideas are connected in a clear sequence.
What will I learn from an article?
You can learn what a technology is, why it appeared, where it is used, how it differs from related ideas, and what to consider before using it.
Do these guides replace official documentation?
No. What Is is a starting point. Always consult current official documentation for implementation, configuration, licensing, security, and other decisions that depend on exact conditions.
Will new topics be added?
Yes. New explanations are added around topics people frequently search for or repeatedly encounter while learning and working.