It's potentially both.

Sexuality is confusing, since it's commonly two distinct things that we look upon as 'sexuality.' If everyone sticks to the gender roles conventionally dictated by their sex, then the two tend to align quite nicely: in a world where everyone with a penis takes on the role of 'man' and everyone with a vagina takes on the role of 'woman', straight is synonymous with heterosexual and gay is synonymous with homosexual. But once people stop doing that, the correlation begins to fall apart.

So first of all, there's actual sexuality. This is one of asexual, bisexual, heterosexual or homosexual, and in most cases (some exceptions for intersex and some transsexual people) is broadly defined based on what's in your underpants, and whether someone else having the same or other bits in their underpants is a deal breaker. There are four possible permutations of same and other sex interest, and so asexual, bisexual, heterosexual and homosexual are the only true sexualities (special cases being gynosexual and androsexual, which are alternative expressions of homosexual and heterosexual but without defining the sex of the interested party.)

But sexuality as we generally understand it doesn't stop there. It also factors in gender based attraction. This follows a range of straight, through pan, to gay. This is about your attraction to gender in relation to your own gender. Same, both or other respectively. There doesn't seem to be a commonly recognised 'neither' option on this scale, as yet.

So all of a sudden, we have 12 permutations of sexuality: (alphabetically, so as not to show any favoritism.)
Gay asexual
Gay bisexual
Gay heterosexual
Gay homosexual
Pan asexual
Pan bisexual
Pan heterosexual
Pan homosexual
Straight asexual
Straight bisexual
Straight heterosexual
Straight homosexual

Or to look at it another way, the Kinsey Scale now becomes a chart with a second axis of gender based attraction.

So yes, if you have a penis and you enjoy sex with people who have penises and people with vaginas, then on the first score, you're bisexual. If you don't care about their gender presentation, then you're also pan. But if, for example, you were sexually interested in both people with penises and people with vaginas, but (as someone with a masculine gender identity) were only interested in feminine presentation, then you'd be straight and bisexual.

These are the sexualities that I recognise, and you can identify as any one of the options, depending on whether your primary criterion is sex or gender, or you can reasonably identify as one from each list. As long as we can knock all of this 'sapiosexuality' and similar nonsense on the head, otherwise I'm declaring myself fiscosexual in the hope of finding a rich boyfriend.

Just words. Some people think of themselves as liking "both" sexes, and feel strongly that there are only two to choose from, so the term bisexual might be prefered. Others feel sex is a spectrum, and they like having sex with all kinds of people, so they choose pansexual.

The way I see it, if you’re attracted to more than one sex, you’re bisexual. I consider pan as a subset of bisexuality.

I kinda gave up on the labels years ago. What word I use makes no difference on who I do or do not find attractive.

Well Bisexual is more the physical attraction I think. Pan is an attraction to personality rather than the physical bodies.