On the Earth today there are approximately 600,000 different types of plants and over one million different kinds of animals. Remember that one of the goals of geographers is to understand how lifeforms are distributed throughout the Earth. With nearly 2 million different types of lifeforms on Earth, the task of mapping out and understanding their distribution can be overwhelming.
In order to aid them in their goals, geographers group lifeforms into categories based on how they are the same and how they are different. For the purpose of geography, the two main groups are flora and fauna.
Flora consists of all the plant life on Earth, while fauna refers to animal life.
Within the oceans, geographers sometimes categorize lifeforms a little differently. Instead of two major groups, they consider three. These are plankton, nekton, and benthos. Plankton consist of any plants and animals that float in the water. Nekton are the animals, such as fish, squid and sharks that can swim about freely from place to place. Benthos are the plants and animals found on the ocean floor.