人 is Chinese character ひと is Hiragana like alphabet in English. They have same meaning of "people or person" You don't need to use them separately. かいしゃのひと means "person in company". I'm not good at English. sorry if I can't make you understand.T.T

人 means person. ひと is one of the ways you can pronounce 人. More specific, it is the so called Kun-pronunciation, which means that this is the way the word sounded in ancient Japanese (give or take all kinds of changes in thousands of years). Alternatively, you can use the On-pronunciation, which is the sound associated with the Chinese character 人, and this is じん. The current Chinese pronunciation of this word is transliterated as REN, so there is some similarity left. The trick is now to know when to use which pronunciation. In general, when two kanji are next to each other without hiragana, you use On, and if the word is on its own, like in your sentence which reads 会社の人 in kanji, you use Kun. But of course there are lots of exceptions. Here are some examples with 人: 人：ひと person 外国人：がいこくじん foreigner 村人：むらびと villager (the ひ is changed into a び) 人差し指：ひとさしゆび index finger (body parts are very often Kun-pronounced)

ひと is basically the phonetic way of saying same thing. The other is the kanjI.