1. Entropy

2. Entropy = Disorder
Entropy (at the level we will be discussing it), can be simply defined as DISORDER.
Disorder (in the natural world) has to do with two concepts:
How dispersed (spread out) matter and energy are.
How faster matter is moving.
Generally speaking, the more dispersed things are and the faster they are moving, the more disordered they are.

3. Examples of Increasing Entropy
Anything breaking into pieces.
Room getting messy.
Binder getting disorganized.
Riots.

4. Examples of Decreasing Entropy
Cleaning your house, room.
Creating and following a schedule.
Assembling a piece of furniture.
Sitting according to a seating chart.

5. Entropy & the Phases of Matter
Solid  Liquid  Gas
(increasing energy & speed of molecules)
Any process that goes in this direction involves an increase in entropy.
Solidliquid (melting)
Liquidgas (evaporation)

6. Entropy & the Phases of Matter
Any process that goes in the opposite direction involves a decrease in entropy.
Gasliquid (condensation)
Liquidsolid (freezing)

7. The 2nd Law of Thermodynamics
While entropy most certainly decreases in plenty of situations, the entropy of the universe overall is CONSTANTLY INCREASING.
This basically reflects the fact that the universe is expanding and that its energy is constantly becoming more and more dispersed.