1.2 Data models and query languages - KeynesYouDigIt/Knowledge GitHub Wiki
from Designing-Data-Intensive-Applications
NoSQL
Its a better version of older document stores, great for loosely structured and or non-related data
SQL
The OG, by far the most common. Heavily structured and schematized. Still in use and probably will be for schematized data forever.
Graph
Quickly rising, excellent for data where the relationships are more important than the underlying data AND OR relationships often follow many points, not just one. Invented to deal with social networks, can be used for much more.