What it is: A managed relational database service (MySQL, PostgreSQL, MariaDB, Oracle, SQL Server).

What it’s for:

• Run relational databases without managing OS-level database operations.
• Get managed backups, patching, monitoring, and HA options.

Key ideas:

• HA option: Multi-AZ (standby in another AZ, automatic failover).
• Scale reads: Read Replicas.
• Automated backups and snapshots.

Exam cues:

• “relational DB, managed, automatic backups” → RDS.
• “survive AZ outage, same endpoint” → RDS Multi-AZ.

Hard words (English + IPA + Vietnamese meaning):

• *relational* /rɪˈleɪʃənl/: quan hệ (SQL)
• *patching* /ˈpætʃɪŋ/: vá/cập nhật
• *high availability (HA)* /haɪ əˌveɪləˈbɪləti/: tính sẵn sàng cao
• *endpoint* /ˈendpɔɪnt/: điểm truy cập (host/URL)