They are the considered thinking positions of groups of people on some particular matter. People have their own personal philosophies. Whether one joins a group or keeps it to themselves, people have convictions on such things as how to coach basketball or what is the meaning of life. Capitalism, and Animal Rights, Fitness and Secular Humanism are philosophies because they are what people have decided is the true and best answer to a specific issue. Philosophy, then, whether that of professionals or of groups, or of any one person in particular refers to their thinking on p73 something.
Philosophy is another word for thinking.
The capacity to think is a power we humans possess. When activated, it is a process, an activity. Its primary existence lies not in books, nor in curriculum courses or only in the mind of professional philosophers but rather in the minds of thinking people. The result, if only temporary, of the activity of thinking is a conclusion or position. Upon thinking about something a person forms a judgment, an opinion, a conviction, claims that they know something of the truth and the goodness of some matter.