The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.
A pH of 7 is neutral. A solution with a pH of 7 is known as neutral solution, such a solution has equal concentration of H+ and OH- concentration. The OH- concentration balances the H+ concentrations in the solution making it neutral.
Pure water is an example of a solution that is neutral, has a pH of 7.