Multiplexing
ELI5 — The Vibe Check
Multiplexing sends multiple requests over a single connection simultaneously. Instead of opening 6 connections for 6 files, you send all 6 over one connection interleaved. It's like having one highway lane that carries packages for 6 different deliveries at once, weaving them together.
Real Talk
Multiplexing in HTTP/2 and HTTP/3 allows multiple request-response pairs to be in-flight simultaneously over a single TCP/QUIC connection. Frames from different streams are interleaved, eliminating HTTP/1.1's head-of-line blocking at the application layer. HTTP/3 solves it at the transport layer too.
When You'll Hear This
"HTTP/2 multiplexing means we don't need domain sharding or sprite sheets anymore." / "Multiplexing over one connection is more efficient than opening 6 parallel TCP connections."
Related Terms
Connection Pooling Pattern
Connection Pooling keeps a bucket of pre-opened database (or HTTP) connections ready to use. Instead of opening a new connection for every request (slow!
Head-of-Line Blocking
Head-of-Line Blocking is when one slow request blocks everything behind it, like a slow car in a single-lane tunnel. In HTTP/1.
HTTP/2
HTTP/2 is a supercharged version of HTTP. With HTTP/1.1, you could only ask for one thing at a time per connection.
HTTP/3 Features
HTTP/3 ditches TCP for QUIC (built on UDP), which means no more head-of-line blocking, faster connections, and built-in encryption.