**Entropy **

What
is entropy? From a microscopic point of view

What is entropy? From a macroscopic point of view

__Comments__:

Entropy is a
very important concept in physics. The first article explains what entropy is
and why it ¡°always¡± increases. The second article explains what entropy is from
a macroscopic point of view. It can be read independently of the first one.
These articles serve as prerequisites for the section ¡°Statistical Mechanics.¡±