one presume your asking ,what is it about soap that makes it clean stuff?
(the question is not well worded, but ain't it amazing how little imagination some folks have )
traditional soap contain oil and lye that have been mixed,and gone through a reaction that unites them.
what they do is surround dirt and oil with a bubble a caustic oil ,that water is mostly able to wash off.
detergent ,o the other hand ,reduce the surface tension of water,so that it (water) surround dirt and oil ,and wash them away.....