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Systems Glossary

43 terms across 7 categories — from HTTP basics to distributed systems patterns. Search for anything.

43 Terms

HTTP & APIs

API

Deep Dive →

A defined contract for how software components communicate.

Infrastructure

API Gateway

Deep Dive →

A single entry point that routes requests to the right backend service.

Security

Authentication

Deep Dive →

Verifying who you are (identity).

Security

Authorization

Deep Dive →

Verifying what you're allowed to do (permissions).

Networking

Bandwidth

Deep Dive →

The maximum data transfer capacity of a network connection.

Performance

Cache

Deep Dive →

A fast-access storage layer that stores frequently used data.

Performance

Cache-Aside Pattern

Deep Dive →

Check cache first; on miss, fetch from DB and update cache.

Infrastructure

CDN

Deep Dive →

A global network of servers that deliver content from the closest location.

Architecture

Circuit Breaker

Deep Dive →

Automatically stops calling a failing service to let it recover.

Databases

Database

Deep Dive →

A system for persistently storing and querying structured data.

Databases

Database Index

Deep Dive →

A data structure that speeds up queries at the cost of write overhead.

Networking

DNS

Deep Dive →

Translates human-readable domain names to IP addresses.

HTTP & APIs

Endpoint

Deep Dive →

A specific URL that handles a particular type of request.

Architecture

Fault Tolerance

Deep Dive →

The ability of a system to continue operating despite component failures.

Architecture

High Availability (HA)

Deep Dive →

Designing systems to minimize downtime and keep services running.

Infrastructure

Horizontal Scaling

Deep Dive →

Adding more server instances to handle more load.

HTTP & APIs

HTTP

Deep Dive →

The protocol used to transfer data on the web.

HTTP & APIs

HTTP Headers

Deep Dive →

Metadata attached to HTTP requests and responses.

HTTP & APIs

HTTP Status Codes

Deep Dive →

3-digit codes in every HTTP response indicating success or failure.

HTTP & APIs

HTTPS

Deep Dive →

HTTP with encryption. Secure version of HTTP.

Networking

IP Address

Deep Dive →

A unique numerical address identifying a device on a network.

HTTP & APIs

JSON

Deep Dive →

The universal format for exchanging structured data between systems.

Security

JWT

Deep Dive →

A compact, self-contained token for transmitting identity claims.

Performance

Latency

Deep Dive →

The time delay between sending a request and receiving a response.

Infrastructure

Load Balancer

Deep Dive →

Distributes incoming traffic across multiple servers.

Architecture

Microservices

Deep Dive →

An architecture where a system is split into small independent services.

Architecture

Monolith

Deep Dive →

A single application that contains all functionality in one deployable unit.

Databases

NoSQL

Deep Dive →

Non-relational databases with flexible schemas.

Databases

PostgreSQL

Deep Dive →

A robust, full-featured open-source SQL database.

Performance

Rate Limiting

Deep Dive →

Restricting how many requests a client can make in a time window.

Databases

Redis

Deep Dive →

An in-memory key-value store used for caching and real-time data.

HTTP & APIs

Request / Response

Deep Dive →

The fundamental interaction pattern of HTTP communication.

HTTP & APIs

REST

Deep Dive →

A design style for building APIs using HTTP conventions.

Infrastructure

Reverse Proxy

Deep Dive →

A server that sits in front of backends and forwards client requests to them.

Security

Signed URL / Valet Key

Deep Dive →

A pre-authorized URL with a time-limited access token for a specific resource.

Databases

SQL

Deep Dive →

The language for querying and managing relational databases.

Networking

TCP

Deep Dive →

A reliable, connection-based transport protocol that guarantees delivery.

Performance

Throughput

Deep Dive →

The number of requests a system can handle per unit of time.

Security

TLS / SSL

Deep Dive →

Encryption protocol that secures data in transit.

Performance

TTL

Deep Dive →

Time To Live — how long cached data stays valid before expiring.

Infrastructure

Vertical Scaling

Deep Dive →

Making a single server more powerful by adding CPU/RAM.

Infrastructure

Web Server

Deep Dive →

A program that listens for HTTP requests and sends back responses.

Networking

WebSocket

Deep Dive →

A persistent, full-duplex connection for real-time communication.