====== Network Load Balancer (NLB) ======

**What it is:** A Layer 4 load balancer for TCP/UDP traffic.

**What it’s for:**
  * Very high performance, low latency.
  * Stable IP addresses (useful for some clients).
  * Non-HTTP protocols.

**Key ideas:**
  * Works at connection level (TCP).
  * Often used for high-throughput, real-time apps.

**Exam cues:**
  * “TCP traffic, ultra low latency” → NLB.

**Hard words:**
  * *layer 4* /ˈleɪər fɔːr/: tầng vận chuyển (TCP/UDP)
  * *throughput* /ˈθruːpʊt/: thông lượng
  * *stable* /ˈsteɪbəl/: ổn định