How do you know the difference between generations and individuals

Generations are all of the people born and living at about the same time, regarded collectively or the production of something. Whereas, individual is
a single human being as distinct from a group, class, or family or a single member of a class.

Can you put the picture?

This bacteria must be very strong as it has a large amount on antibiotic targeting it. this bacteria could be one of many different types and it is very hard to tell which one with out more information.