====== User Data ======

**What it is:** A script/commands you provide at launch that run automatically on first boot.

**What it’s for:**
  * Install packages, pull code, configure services at startup.
  * Bootstrap instances in an automated way.

**Key ideas:**
  * Runs once at instance initialization (by default).
  * Common for installing web servers, setting environment configs.

**Exam cues:**
  * “install software automatically when instance launches” → user data.

**Hard words:**
  * *bootstrap* /ˈbuːtstræp/: khởi tạo tự động ban đầu
  * *initialization* /ɪˌnɪʃələˈzeɪʃn/: quá trình khởi tạo