What is a license?¶

Simply stated a license is the permission to undertake some activity.
The most familiar license is a drivers license. Such a license grants the permission to operate a motor vehicle. That license however does not come for free. There are duties and obligations that come along with that grant of permission. For example, we have to obey the rules of the road, in the event we don’t, in addition to fines, sanctions can include license revocation.
It is important to note that the license is not a contract.
With a license there is no bargain for exchange, rather there are stated requirements incident to the license. You either comply or you don’t. If you comply, you have the authority to undertake the action specified under the license. If you don’t comply, then such authority is either not granted or it is revoked
A license can also confer permission to use and possess property. Software is a form of property, and specifically intellectual property, and the ability to use software comes by way of a license.
You may be familiar with the term end-user license agreement or EULA. Here we have both terms license and agreement. Some open source licenses are deemed to be pure contracts.

Open Source Licensing