When someone buys a commercial piece of software, such as Microsoft Office, he or she is bound by a copyright license that specifies how many machines the buyer can load with the software. Thus, a license agreement for a single user allows the buyer to load the software onto one machine (including laptop if the person has one), and to make a back-up copy just in case something happens to the original disk or CD-ROM (compact disc-read only memory).

Business and Personal Concerns

Companies that want all of their employees to use a particular software must buy a site license. Often, a site license allows the buyer to network the software, so that each user can log on to the company network and access the program. Each user on a network is called a client; a software package such as Microsoft Office cost each...