How is the internal linking different from external linking?

In terms of engines, an external combustion engine such as a steam engine burns fuel outside of the pressure cylinder used to drive the piston. An internal combustion engine such as a petrol or...

Internal is inside the organism External is the surroundings and stuff that happens outside the organism

internal happens inside the body and in landexternal happens outside the body and in water

External fertilization would be a fish laying unfertilized eggs and the male depositing sperm on top of the eggs, which fertilize the eggs out of the female fish's body, or externally. Internal...

external forces would be someone lifting something like a book, internal forces would be raising your kinetic energy by raising the mass of an object and releasing its energry