A heterogeneous mixture is a mixture in which the composition is not uniform. It consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers. Other examples include; 

• Soil (containing sand, pebbles, and organic matter). 

• Blood (containing red blood cells, white blood cells, platelets, and plasma). 

• Sand and water. 

• Vegetable soup (you can see the different vegetables and broth) etc