The camouflage is defined as the property of the living organisms that make them to prepare their body to perfectly match with their surroundings so that they cannot be recognised by their hunters. This makes them survive more in an environment with full of competition.
The competition is an interaction between the organisms where in a particular environment, different organisms compete for a particular prey for their living. Here the theory of the survival of the fittest work.
The symbiosis is an interaction between two or more species which leads to benifit of both the species in their living. Here one species help other in a form and other species do the same. There's benifit for both in the interaction.
Endocrine secretion is when a molecule(usually a hormone) is secreted into the blood. Endo as “in” the blood. Exo as “out” of the blood. You can think of it that way if it helps:)
