A license refers to the right to use software legally. Different software manufacturers have very different licensing methods, but licenses are commonly either user-based or machine-based. Simply purchasing an installation CD often does not include a license and therefore does not entitle the user to use the software.
A font is also a software product, the use of which always requires a valid license. The required license is determined based on the intended use. The basic license (EULA) includes workstation/user-specific usage rights. Separate licenses are also required for web, server, and mobile use.
Product packages, also known as retail packages, include both the installation CD and the usage rights. These packages are commonly labeled as 'Full'.