copper conducts electricity through electrons, whereas salt solution conducts electricity through ions.do you agree.why?

Yes it is true that copper conducts electricity through electrons, whereas salt solution conducts electricity through ions.

The common thing is any material with free movement of electrons conducts electricity. Ion is an atom or molecule has total no. of electrons not equal to total no. of protons. Ions are charged particles either positive or negative. Electrons are negatively charged particles.

In copper there are no ions but electrons are present and the flow of these electrons help to conduct electricity and in salt solution ions are present negative ions move towards the anode and positive ions towards cathode simultaneously help electrons to move freely around the circuit which in turn lead to electrical conductivity.