What's the difference between databases, datasets and data collections?
A database is a body of data on a particular subject from a particular publisher. For example:
- Prices for 1000s of futures contracts from the Chicago Mercantile Exchange: CME
- Earnings Surprises for 6000 stocks from Zacks Investment Research: ZES
- Tourism Data for 100s of countries from the United Nations: UTOR
Quandl has over 300 free databases, and a further 20 "premium" databases that are available only to paying subscribers.
A dataset is a single time series contained within an entire database. A database is therefore composed of datasets. Here are some examples of datasets found within a database:
- WTI Dec 2014 crude oil futures price: CME/CLZ2014
- AAPL earnings surprises: ZES/AAPL
- Inbound tourist visits to Australia: UTOR/INTUR_AUS
A dataset can have one column -- for example, US GDP -- or it can have many -- for example, AAPL stock open/high/low/close.
Data collections are groups of related datasets or databases on specific subjects, curated by Quandl users. Here are a few data collections:
You can click through from any data collection to see the underlying datasets and databases.