====== Cost Explorer ======

**What it is:** A tool to visualize, analyze, and break down AWS costs and usage over time.

**What it’s for:**
  * Find which services/regions/accounts cost the most.
  * Detect cost spikes and trends.
  * Plan optimizations.

**Key ideas:**
  * Supports filtering and grouping (by service, tag, linked account).
  * Useful for monthly reviews.

**Exam cues:**
  * “analyze which service increased cost” → Cost Explorer.

**Hard words:**
  * *visualize* /ˈvɪʒuəlaɪz/: trực quan hóa
  * *break down* /breɪk daʊn/: phân rã (chia nhỏ)
  * *trend* /trend/: xu hướng
  * *spike* /spaɪk/: tăng đột biến