Osmosis is the process by which liquids move through a semi permeable membrane from a lower concentration gradient to an higher one.
During the process of osmosis, water for instance, will move through a semi permeable membrane from a region of lower solute concentration to the region of higher solute concentration. In osmosis, water usually leave the region of low salt solute and move instead to the region of more concentrated solute. The liquid will move until the salt solute concentration is the same at either side of the membrane.