Answer
The similarity between substances and solutions is that they both have a uniform composition. And a difference between substances and solutions is that a substance has a definite composition. While a solution is a mixture made by physically combining two or more substances
Work Step by Step
Substances and Solutions both have particles in them thus they have a composition, however substances are made of one kind of particle thus there are definite, while solutions are made of more than one kind of particle thus there are a mixture.