A friend of mine used to refer to fennel as “celery that tastes like something.” And that taste is similar to licorice or anise (anethole is the chemical to thank for this). The entirety of the plant can be used: bulb, stalks, and fronds. The stalks are most similar to celery and can be fibrous. Chopping and cooking can help mitigate that. The fronds can be used as you would any other herb. The bulb is what most fennel recipes will call for and can be used in a variety of ways. I like to slice it thinly and toss with oil and vinegar for a salad. I also like to sauté or braise it, as it caramelizes really nicely.