TCP Handshake
ELI5 — The Vibe Check
The TCP handshake is the 'are you ready?' dance before TCP data flows. It's a three-step process: your computer says 'SYN' (hello?), the server says 'SYN-ACK' (hello, ready!), and you say 'ACK' (great, let's go!). After that, data can flow reliably.
Real Talk
The TCP handshake (three-way handshake) establishes a connection between two hosts. It synchronizes sequence numbers and confirms both ends are ready to communicate. The process: client sends SYN, server responds with SYN-ACK, client sends ACK. Only then can data transfer begin.
When You'll Hear This
"The TCP handshake adds one round-trip of latency before any data is sent." / "SYN flood attacks exploit the TCP handshake to overwhelm servers."
Related Terms
Latency
Latency is the delay before data starts moving — the time it takes for a request to go from your device to the server and back.
TCP (Transmission Control Protocol)
TCP is like sending a package with delivery confirmation.
Three-Way Handshake
The three-way handshake is the official name for how TCP sets up a connection in exactly three steps: SYN, SYN-ACK, ACK.
TLS Handshake (Transport Layer Security Handshake)
The TLS handshake is the 'hello, do we trust each other?' ceremony that happens before any HTTPS data flows.