it - it is pronounced with short "i" [i t]
eat - it is pronounced with long "i" [ i: t]
The main difference in conversation between the two words can be made in the context they are used
it - a pronoun
eat [ ate- eaten] - an irregular verb
We eat out whenever we have time.
It is not such a big deal if we don`t have time to eat out ; we can do it at home this time.
Mother: Eat it up, John!
John I can`t eat it . I don`t like it.
Student or Learner