Glossary

A declared connection in wrangler.jsonc that makes a Cloudflare resource (KV namespace, D1 database, R2 bucket, secret) available to your Worker code via the env parameter.

The actual milliseconds your Worker code spends executing on the processor, excluding time spent waiting for network I/O like fetch() calls or DNS lookups.

A scheduled invocation of a Worker using standard 5-field cron syntax, allowing code to run on a time-based schedule without an incoming HTTP request.

A Cloudflare feature that automatically creates DNS records, issues SSL certificates, and routes traffic from your own domain to a specific Worker.

Cloudflare's serverless SQLite database that runs at the edge, providing full SQL support with ACID transactions, schema migrations, and zero-configuration connectivity via bindings.

Stateful, single-threaded objects with their own SQLite storage that handle real-time coordination such as WebSocket connections, chat rooms, and collaborative editing.

Cloudflare's globally distributed infrastructure of 300+ data centers where Workers execute, placing compute milliseconds from end users rather than in a single origin region.

KV's replication model where writes propagate to all 300+ edge locations within approximately 60 seconds, meaning reads from other locations may serve stale data briefly after a write.

Cloudflare's globally distributed, eventually consistent key-value store optimized for read-heavy workloads with a simple get/put API.

Cloudflare's message passing system enabling reliable producer-to-consumer communication between Workers for background job processing.

Cloudflare's S3-compatible object storage with zero egress fees, designed for storing and serving files, images, and backups without bandwidth charges.

The scheduled(event, env, ctx) export in a Worker that runs when a Cron Trigger fires, as opposed to the fetch handler which responds to HTTP requests.

Cloudflare's vector database for storing and querying vector embeddings, enabling semantic search and AI applications at the edge.

A method on the execution context (ctx.waitUntil(promise)) that keeps a Worker alive until asynchronous background work completes, even after the response has been sent.

A binary instruction format that allows languages like Rust, Go (TinyGo), and C/C++ to compile and run inside the Workers runtime alongside or instead of JavaScript.

A serverless JavaScript/TypeScript/Python/Rust program that runs on Cloudflare's edge network, intercepting HTTP requests and returning responses with automatic scaling and no server management.

The default subdomain Cloudflare provides for deployed Workers (e.g., my-worker.my-account.workers.dev) before a custom domain is configured.

Cloudflare's official CLI tool for scaffolding, developing locally, testing, and deploying Workers and their associated resources.

The configuration file for a Worker project that declares the Worker's name, entry point, compatibility date, bindings (KV, D1, R2), triggers, and route mappings.