Translation:They are people and we are people!
Have you noticed how verbs in Polish change form depending on the person? This is the same thing with the verb "być", and this mechanism is also observed in some other languages you've learned: Portuguese, German, Italian, and Spanish. Although it's true that the third person plural form for this verb looks a bit different from forms for other persons.
In English this is much simpler, with "are" being used for all plural person, and even for the second person singular. This is why you must remain cautious when translating any verb into Polish.