'Works' in the Bible

I have seen all the works that have been done under the sun, and lo, the whole is vanity and vexation of spirit!

I made great my works, I builded for me houses, I planted for me vineyards.

and I have looked on all my works that my hands have done, and on the labour that I have laboured to do, and lo, the whole is vanity and vexation of spirit, and there is no advantage under the sun!

And I have seen that there is nothing better than that man rejoice in his works, for it is his portion; for who doth bring him in to look on that which is after him?

But all this I have laid unto my heart, so as to clear up the whole of this, that the righteous and the wise, and their works, are in the hand of God, neither love nor hatred doth man know, the whole is before them.

Go, eat with joy thy bread, and drink with a glad heart thy wine, for already hath God been pleased with thy works.