Water is a pure substance. This is because it has the same material all over and is made of one kind of substance throughout. Moreover, water cannot be separated into other materials.
Water is a compound that contains two different elements: hydrogen and oxygen. When salt is added into water, it becomes a mixture. Since it has the same features all throughout, it is called a homogeneous mixture or solution. This is in contrast with a heterogeneous mixture. Water can be physically segregated from salt via methods such as filtration. Water, which is colorless and odorless, has a freezing point of 32 degrees Fahrenheit and a boiling point of 212 degrees Fahrenheit.