Both "vyrábět" -- the verb used here -- and "vyrobit" mean "to produce, to make, to manufacture." The first is imperfective, suggesting an action in process or repeated action, while the second is perfective, suggesting a single or completed action. Perhaps one of the Czech experts will provide a more comprehensive explanation
When looking up 'vyrábět' in the dictionary, some tell me that the 3. pl. of it is 'vyrábějí' and some that it is 'vyrábí' like it is here. Can someone explain to me why?
Get a better, or more current, dictionary. As explained many times for similar verbs (4th class, type sázet) originally only -ějí was possible but the language has a tendency to simplify by analogy with other verb types and allows -í now as a more progressive variant. http://prirucka.ujc.cas.cz/?slovo=vyr%C3%A1b%C4%9Bt https://cs.m.wikibooks.org/wiki/%C4%8Ce%C5%A1tina/Slovesa_4._t%C5%99%C3%ADdy