Entropy and the Second Law of Thermodynamics relate to life because life is made possible by the flows of energy implicit in the second law and the selective storage and manipulation of the biochemistry made possible by those flows.
Living organisms are low entropy
In classical thermodynamics, entropy is a measure of the thermodynamic energy availability of a system. Thus a low entropy system has energy available in a form that may be used to perform work while a high entropy system has relatively less energy available. Alternately, entropy can be seen as a measure of disorder where low entropy means a relatively ordered system and high entropy means a disordered system. Finally, in statistical mechanics, entropy can also refer to information content where low entropy means relatively higher information content than high entropy.
Living organisms are low entropy by all three related measures. The more complex the organism, the more true this statement is. Live organisms store energy and make it available for metabolic processes to move, eat, think, etc. Organisms are highly ordered systems, the most complex systems we have seen in the universe thus far. Organisms also have very high information content. Organic systems are controlled through a complex intermix of chemical, electrical, and genetic information that we do not even fully comprehend at this point, even for the most basic single celled organisms. They are the most highly ordered systems known.
The second law of thermodynamics is
somehow strongly connected to the
origin of life itself.
The second law of thermodynamics states that in a closed system, entropy will tend to increase and that entropy will flow from the low entropy region to the high entropy region. This relates to life in two specific ways:
It makes life less likely, in general, since life must originate through a random fluctuation to a low entropy state. Since entropy normally increases, over time the entropy of the system will be higher and therefore less likely to originate life.
It makes life more likely on a planet like Earth that sits in the middle of the entropic gradient of the entropy flows from the very low entropy Sun outward to the relatively higher entropy solar system. The surface of the ocean is the edge of a very steep thermodynamic gradient where the energy from the sun mixes with the relatively cool water of the ocean. In these gradients, it is much more likely for random fluctuations to result in a very low entropy molecule like an amino acid or eventually DNA because there is a continuous energy flow from the Sun through the gradient. This energy makes possible various endothermic chemical reactions, increases the rate of chemical reaction, and offers a source of energy for continued conversion for metabolic purposes for any living organisms.
So both statements are true.