Digital typefaces are products distributed and sold like software: it is not the design itself that is sold, but a copy (a font) attached with an agreement to use it: its license.

When purchasing a license, a specific EULA (End User License Agreement) is attached, containing all the terms and conditions of use granted by the distributor, foundry or designer for each font.
Different EULAs and licensing terms can exist according to the politics and principles of each entity. It is always advised to contact the foundry or the distributor if there is any doubt or question related to the terms in the EULA, to be sure that the license and EULA are valid for the intended use.