Living organisms are distributed over the entire surface of the planet. The distribution of the individuals of each species is not random; on the contrary, they are strongly dependent on the biology and ecology of the species, and vary over different spatial scale. The structure of whole populations reflects the location and fragmentation pattern of the habitat types preferred by the species, and the complex dynamics of migration, colonization, and population growth taking place over the landscape. Within these, individuals are distributed among each other in regular or clumped patterns, depending on the nature of intraspecific interactions between them: while the individuals of some species repel each other and partition the available area, others form groups of varying size, determined by the fitness of each group member.

The spatial distribution pattern of individuals again strongly influences the outcome of ecological processes. For instance, interactions between predator species and their prey can have widely different population impacts in different landscapes.

At the very largest scales, the position and sizes of the entire range of species also follow characteristic patterns. The study of these patterns is becoming an important instrument in the conservation and protection of global biodiversity.