Sheol in the old testament has the same meaning as Hades in the new testament. You can see this by the following textual agreement:
KJV Psalm 16:10 For thou wilt not leave my soul in hell; neither wilt thou suffer thine Holy One to see corruption.
LXT Psalm 15:10 ὅτι οὐκ ἐγκαταλείψεις τὴν ψυχήν μου εἰς ᾅδην οὐδὲ δώσεις τὸν ὅσιόν σου ἰδεῖν διαφθοράν
WTT Psalm 16:10 כִּ֤י׀ לֹא־תַעֲזֹ֣ב נַפְשִׁ֣י לִשְׁא֑וֹל לֹֽא־תִתֵּ֥ן חֲ֜סִידְךָ֗ לִרְא֥וֹת שָֽׁחַת׃
KJV Acts 2:27 Because thou wilt not leave my soul in hell, neither wilt thou...