Database

RDBMS / SQL

NoSQL: - neo4j (graph) - mongoDB (document) - cassandra - redis - dynamoDB (key-value)

ACID: - Atomicity (all-or-nothing) - Consistency - Isolation - Durability

CRUD: - Create - Read - Update - Delete

sharding vs replication

CAP theorem: - Consistency - Availability - Partition (Network)

PAC ELC theorem:
Partition, yes (PAC): - Availability - Consistency no (ELC): - Latency - Consistency