Learn in the textbookSoftware Distribution and Usage Models
DefinitionActivation (アクティベーション) is the procedure of license authentication (ライセンス認証) that lets software run on the device of a user who bought it legitimately.
ExplanationWhen you enter the product key (プロダクトキー, an identification number unique to each purchased license) received at purchase, that number and information about the device are sent to the vendor and checked. Some products limit their features, or will not start at all, until authentication is complete. The main purpose is to prevent misuse such as running one license on more devices than allowed.
AnalogyIt is like verifying your identity to switch on a newly delivered credit card before you start using it.
Memory hookTo activate is to set something in motion: the software comes to life only after authentication.