Variation is how similar or different living things are from each other. For example: in a class of students, some may be tall or short and have different coloured eyes, skin, hair. These are generally inherited characteristics (unless you've been having fun with hair dyes!), whilst other variations are the cause of your environment - for example: your skin colour might be inherited or it might be temporarily different as you've just returned from a holiday in Spain!
This worksheet looks at different aspects of variation and how we might be able to measure them to see how they vary within a group of people.