Redis
ELI5 — The Vibe Check
Redis is an incredibly fast database that lives entirely in memory (RAM). It's used as a cache, a session store, and a message queue. Because it never touches the disk, it's 100x faster than a regular database. The catch: RAM is expensive, so you only store hot data there.
Real Talk
Redis (Remote Dictionary Server) is an open-source, in-memory data structure store that supports strings, lists, hashes, sets, sorted sets, and more. Commonly used for caching, session management, pub/sub messaging, leaderboards, and rate limiting.
When You'll Hear This
"Store the session in Redis." / "Use Redis to cache the query results." / "The rate limiter uses Redis to track request counts."
Related Terms
Caching
Caching is saving the result of a slow operation so you can reuse it quickly next time.
Memcached
Memcached is Redis's simpler sibling — an in-memory cache that's great at one thing: storing key-value pairs really fast.
Pub/Sub (Pub/Sub)
Pub/Sub is like a newspaper service. Publishers write articles and drop them off.
Queue
A queue is like a line at a coffee shop — first come, first served. The first person to get in line is the first to get their coffee.
Session
A session is the server's way of remembering who you are across multiple requests.