What is Open Data ?
Open Data is defined as structured data that is machine-readable, freely shared, used and built on without restrictions. (Gov of Canada - Open Data). The goal is interoperability.
The key features of openness are:
Availability and access: the data must be available as a whole, preferably by downloading over the internet. The data must also be available in a convenient and modifiable form.
Reuse and redistribution: the data must be provided under terms that permit reuse and redistribution including the intermixing with other datasets. The data must be machine-readable.
Universal participation: everyone must be able to use, reuse and redistribute — there should be no discrimination against fields of endeavour or against persons or groups. For example, ‘non-commercial’ restrictions that would prevent ‘commercial’ use, or restrictions of use for certain purposes (e.g. only in education), are not allowed.
Open data are the building blocks of open knowledge. Open knowledge is what open data becomes when it’s useful, usable and used
Open Knowledge International : https://okfn.org/opendata/
Open Government (Canada): http://open.canada.ca/en/open-data
Open Government (USA): https://www.data.gov/