The difference is that resistivity is a property of a kind of material while resistance is measured for a particular object. In the diagram below on the left, the squiggly line represents a wire. The ohmmeter measures its resistance. On the right we have a shorter wire made of the same material. It has less resistance.
Electricity goes through it more easily because it is shorter.
The resistivity of the material the wire is made of is the same in both cases. Metals have fairly low resistivity and allow electricity to flow easily. That's why electrical wire is made of metal, usually copper. Rubber, glass, air, and most kinds of rock have high resistivity. Materials with low resistivity are called conductors .