Types of computer software
What is software? 
A piece of computer software is a set of computer instructions that tell a computer how it should do something.
System Software 
On most computers there's an operating system, or OS, which defines some of the basics about how your computer should act. The three (3) most common operating systems are Mac OS, Linux, and Windows.
- A program or piece of software designed and written to fulfill a particular purpose of the user.
Software Licenses 
A software license (or software licence in commonwealth usage) is a legal instrument (usually by way of contract law) governing the usage or redistribution of software. All software is copyright protected, except material in the public domain. Contractual confidentiality is another way of protecting software. A typical software license grants an end-user permission to use one or more copies of software in ways where such a use would otherwise potentially constitute copyright infringement of the software owner's exclusive rights under copyright law.
Some software comes with the license when purchased off the shelf or an OEM license when bundled with hardware. Software can also be in the form of freeware or shareware. Software licenses can generally be fit into the following categories: proprietary licenses and free and open source licenses, which include free software licenses and other open source licenses. The features that distinguishes them are significant in terms of the effect they have on the end-user's rights.
A free open source license makes software free for inspection of its code, modification, and distribution. Some free licenses, such as the GNU General Public License (GPL), allow the product and/or derivative to be commercially sold.
What next?