The term commercial has various meanings, depending on the context. One of the most common usage of the word commercial are for TV commercials, which is actually just another term for TV advertisements. Another meaning for commercial is anything that pertains to something for the mass market. And the third use is for pertaining to anything engaged in commerce and having either monetary or non-monetary gain as motive.
Commercial as an advertisement
TV and radio commercials are one of the most common forms of advertisements. Companies pay networks to air their infomercials. Rates usually depend on how big the audience is during the time slot the commercial is aired.
An example wherein the term commercial pertains to mass market appeal is for terms like commercial artist and commercial grade. A commercial artist produces work that even common people can appreciate and will patronize.
This does not indicate inferiority or superiority of the artist’s work, but means that the art is universally appealing or for everyone. Commercial grade, on the other hand, is also for the mass market but means that the quality of something is inferior. Commercial-grade beef, for example, will not be of the best cut. It will be more affordable and accessible to everyone, but obviously of inferior quality to choice cuts.
Any individual or firm that does business for monetary gain is considered commercial. The opposite of such business are non-commercial ones such as non-profit organizations, whose purpose is usually to fund charities.