The second law of thermodynamics says that all things wear down and lose energy over time. This tendency for energy to dissipate and decay over time is called Entropy. If I place a plate of cheese out on the bench, it will remain much the same for a time, but will eventually degrade and decay. Buildings crumble and fall over the centuries, mountains will crumble and the computer I am using to write this paragraph will one day rust and disintegrate.
If I do not clean my house, it will get dirty and start falling apart. If we do not clean. tidy and repair things that are broken, the house will eventually become unliveable.
Entropy increases over time but living systems can hold off the winding down for a significant length of time. Life seems to avoid the tendency to decay by taking in matter, energy, and information from the outside to counteract the degradation inside. Living systems are dissipative because they take energy and dissipate it through the system and back out into the environment. Since this energy is absorbed from the outside, the outside experiences an even greater increase in entropy so that the overall effect, combining the entropy outside and inside, is that there is still a net gain in entropy. A living system becomes an island of order in a sea of chaos. Entropy appears to be overcome within the living system. The name negentropy is sometimes used to describe this overcoming of the tendency to wind down.
Natural environments such as a forest have interconnections and inter-relationships, such that the waste from one system, nourishes and supports the others, so that the forest can remain in dynamic stability for thousands of years. Plants absorb carbon dioxide and release oxygen, while animals absorb oxygen and release carbon dioxide.
Living systems have repair functions built in to repair damage as it inevitably happens. Perturbations from the outside like a disease or injury from a fall cause degeneration. Without a repair function, we would not live long at all. Wounds generally heal over time.
Having cognitive skills allows us to respond more effectively to potentially threatening situations. Humans can predict likely future outcomes and move to avoid unhelpful consequences.
Any living system that is unable to maintain the flow of energy, matter, and information will be overcome by entropy and not survive.