Wine is an application that allows users to execute Windows software via a compatibilty layer. Although the acronym of WINE (Wine Is Not Emulation) describes itself as not an emulator but as a compatabilty layer, many still see it as one.
Wine is geared towards running normal Windows software whereas Steam's Proton is more geared towards playing games at high performance. Trying to run regular Windows software may be troublesome with Proton but is no trouble to Wine. Even some games run better on Wine but struggle or simply don't launch with Proton.
As Wine deals with a foreign format, it is to be expected that it depends on extra toolchains as well as other dependencies. Please check Wine Dependencies before continuing with this chapter.