In this narrow definition, a politician is a person holding or running for elected office, and a political party is a specifically registered organization that is formed with the express intent of organizing voters and politicians, such that the voters vote for the politicians. There's a list on Wikipedia [1].

Of course, this narrow definition leaves out a lot of political issue ads that don't mention candidates or political parties by name, but are still very much political. Things like "support / oppose access to guns / abortion / health care / immigration / education / clean water / fair elections / military service / communication / electricity / there's a lot of other stuff" are quite often political ads without necessarily being tied to any particular candidate or party.

[1] https://en.wikipedia.org/wiki/List_of_political_parties_in_t...