Looking for open datasets? This guide contains a curated selection of open data indexes as well as information on open data.
The Open Data Handbook defines open data as:
Open data is data that can be freely used, re-used and redistributed by anyone - subject only, at most, to the requirement to attribute and sharealike.
To be considered open data it should be in a format that is easy to modify and work with, be reusable - including remixing the data with other data sets - and open for anyone to use with no cost associated. From a governmental standpoint, open data promotes transparency and accountability.