A quick explanation of a simulation game
There exists this simple community, which the narrator decides to represent it with some square boxes. Assuming each of them represents a cat-like person, and each of them can have anyone of the two states, which is either living or dead (or yet-to-be-borned).
Each person's lifelihood, is determined by how many neighbours available. Neighbours are the people surrounding the person. Each evolution may bring in new members to the community, take some of them off, or nothing changes.
This community values neighbours, so the number of neighbours directly determines whether a person is able to survive an evolution. In short,
"Having the right amount of neighbours, you live, otherwise, you die."
There are just 4 rules to be followed, let's go through them 1 by one
We all know what it is like to be left alone, in this community loneliness is so bad that it may cause one to not survive an evolution. The person will be dead if there's only 1 or no one around him.
Just in case you have not noticed, a person's neighbours are the other 8 surrounding cells.
The opposite of loneliness is the feeling of suffocation. When there are too many people around, we lose the personal space we need. The same thing applies in this community, and if there are more than 3 people surrounding a person, then the person dies.
Therefore the optimum number of neighbours, is 2 to 3 people. Everyone has enough room to breathe, and not overwhelmed by too many neighbours around. I would say this is a win-win situation.
A community keeps moving when there are changes to the structure, especially when there's an addition of new members. A new member is born, whenever there are exactly 3 living neighbours around.
There are several patterns discovered when people start playing with the simulation. For instance you have seen one in the example above, where there were no changes happening regardless how many times you hit the evolve button. It was an example of Still lifes.
Here is another pattern discovered by others. You can see the pattern keeps repeating itself after a while. The following pattern is called a blinker, which is an example of oscillators.
And not forgetting spaceships, for example this glider below (press the Automate button to speed it up).
This game is known as the Game of Life. It was created by John Horton Conway and you may want to see this video for more interesting facts about the game.
Finally, you can have a play with the following sandbox. Hit the randomize to generate a board with random living cells.