Interchangeable. Sometimes the second word starts with i - and to avoid i-i we use TA.
thank you so much ! so i can use i , until the 2nd word start with i too right?
No difference whatsoever, in Ukrainian there are several words for "and" purely for the purpose of sounding melodic.
Actually, we also have "й", yet another form of "and", for the case when both words "meet" with vowels. We use these different forms so that the phrase rolls easily from your tongue, with no vowels or consonants clashing.
consonant-consonant: брат і сестра [brat i sestra] (brother and sister)
vowel-vowel: Олена й Олександр [Olena j Oleksandr] (two names)
vowel-consonant: : мама та тато [mama ta tato] (mother and father)