Im goin 2 dominican republic(bavaro) and i have US dollars does this matter, as the local currency is peso's

Question

im really confused cos i been told that they accept US dollars but the local currency is Peso's.

im going to a holiday resort on the east coast beach line, will they accept US dollars their or will i need to change it. . . . asked this question 3 times now sorry if your answering it agian, just want to get if right ?!?!?!?1