A mixture is a substance formed by combining two or more elements in a way that involves no chemical reactions. The elements in a mixture can be easily separated using physical means.
There are two types of mixtures:
Homogeneous mixtures: these are mixtures in which you cannot see the particles of the elements forming it. Examples of homogeneous mixtures: lemonade and coffee.
Heterogeneous mixtures: these are mixtures in which you can see the particles of the elements forming the mixture. Examples of heterogeneous mixtures: oil and water, cereal and milk as well as sand in water.
On the other hand, a compound is a substance formed by the combination of two or more atoms by a chemical reaction. The elements in a compound cannot be separated by physical methods. Examples of compounds: ammonia, acetic acid and methane.