A print publication spearheaded by Hugh Heffner. During the early days, there were Playboy Clubs which were gentlemens clubs with women dressed in satin bunny outfits serving the patrons. A print magazine came shortly after that showcased women in a centerfold. Generally these shots were more glamor oriented rather than the spread pussy shots that Hustler became known for.
Playboy entered the internet arena a little late and has had significant financial problems, but, with the tenacity of a younger Heffner, they are making strides to claw their way back up. They now understand web surfers a little better and are offering content through their site to complement their print magazine.
As a result of this gentleman's club and free lifestyle image, the term "a playboy" came to refer to a single man who might have more than one girlfriend or who might spent time at a gentleman's club.