Software licensing refers to the permissions, rights and restrictions imposed on software components which form part of the Software ecosystem. The license for a specific software component is typically selected by the Copyright holder(s).

The licensee of said component is then permitted to use the software component in compliance with the specific details of the license; they are obliged to comply with the license completely. If there is a breach of the license, this may, depending on the license result in the licensees the use of the component revoked.

A software license is provided by the Copyright holder(s) with the software component following their decision to provide others with a digitally identical copy of the software component.

Licenses vary greatly depending on what the Copyright holder(s) chose to grant as permissions, rights and what restrictions on the licensee are imposed.

An example of a license for which the originators maintain strict control over the software component is the Microsoft Windows Operating System software. This has helped Microsoft successfully gain a dominant position in the software market: Microsoft Licensing.

The GNU GPL is aimed at providing licensees with significant permissions and rights. There are restrictions in the license -- the licensee must pass on the received permissions and rights to anyone to whom they provide the software. Once a piece of software is distributed under the GPL that released copy will always be available with the permissions and rights received.

In some cases software vendors release software under several licenses to suit different users. This may be at a different purchase price.