I'm not sure what you're asking here. A perpetual software license is a software license agreement that has an infinite term, does not expire, or in some cases, automatica … lly renews itself, if so required. Some software licenses have a term, like 30 days, 12 months, etc. A software license agreement functions in a similar capacity to a lease, or rental agreement. It defines how, how long, where, when, etc, a software application can be used and copied. A software purchase is the purchase of a software license. When you purchase software, you are purchasing the right to use, more specifically load the software in the form of a derivative copy. Sometimes, the software you purchase has a perpetual license.. Sometimes, it does not. G.C.