Most people can't answer this question. It's too abstract. It's also controversial. Philosophers themselves can't agree on any answer. Sure, the name "philosophy" derives from the Greek for "love of wisdom", but what's that? There has been a long and glorious history of people called philosophers, but they talk about all kinds of topics in all kinds of ways. It is not clear what, if anything, they have in common that makes them all philosophers.

philosophy studies the fundamental nature of existence, of man, and of man's relationship to existence. … In the realm of cognition, the special sciences are the trees, but philosophy is the soil which makes the forest possible.
—Ayn Rand, Philosophy, Who Needs It