• Filesystems

  The OS-layer abstraction that turns a flat block device into named, permissioned, hierarchical files — covering inodes, paths, permissions, journaling, and copy-on-write.

  w102

• APIs

  A versioned contract between two pieces of software — endpoints, verbs, payload shapes, errors, and auth — that decouples a caller from an implementation.

  w85

• JSON

  Text-based data interchange format derived from JavaScript object literals and standardised as RFC 8259 / ECMA-404.

  w54

• Retrieval-Augmented Generation (RAG)

  Grounding LLM responses in chunks retrieved from an external corpus so the model reasons over real, citable sources instead of parametric memory alone.

  w39

• AI Agents

  LLM-driven systems that pursue a goal by interleaving reasoning, tool calls, and observations inside a loop — and that decide for themselves which step to take next.

  w28

• Asynchronous Programming

  Non-blocking concurrency built on event loops, futures, promises, and coroutines that lets a single thread overlap many in-flight I/O operations.

  w24

• Regular Expressions

  A pattern-matching mini-language for searching, validating, and rewriting text — implemented (with subtly different dialects) by every modern language and CLI tool.

  w24

• HTTP

  The request/response protocol that carries almost every API, page, and download on the modern internet — methods, status codes, headers, caching, and three wire formats (HTTP/1.1, HTTP/2, HTTP/3).

  w21

• Pipes

  An operating-system primitive that streams one process's stdout into another's stdin, letting small composable tools build large data flows.

  w18

• DNS

  The hierarchical, cached, globally-distributed naming system that turns human-readable hostnames into IP addresses, mail routes, service endpoints, and trust anchors.

  w16

Concepts vs. glossary — concepts are synthesis pages about one technical idea; /glossary is an A–Z index of reference articles.