Cohesion is said to be attraction between particle of same type or origin, type of soil where there is inter-particular attraction. In these type of soil particles are very fine and it is governed by surface fore rather than its self weight. Also, the friction between the soil will not happen hence shear strength will be contributed by only cohesive force and not internal friction.
Non-cohesive soil -soil with out cohesive force, has coarser particles with self weight governing their behaviour. The soil particle has internal friction and shear strength depends on internal friction between their sand particles.
Most natural soil have both cohesive and frictional force contributes shear strength.