Bi means you experience attraction to two genders typically, but some people use it to mean attraction to more than two, sometimes with a preference.
Polysexual and polyromantic are two or more genders and an umbrella term, pan means you are attracted to all genders and the gender does not affect your feelings at all, and omni means you are attracted to all genders but the gender affects your feelings.
And, in case you're confused by poly for hearing something else, there is a term called polyamorous for being attracted to more than one person at a time.