0.0.0.0 - if the fourth number changes, it means there was a bug or some fixes.

0.0.0.0 - if the third number changes, it means there is a new small feature or a fixed bug.

0.0.0.0 - when the second number changes, there is something new (like night or something)

0.0.0.0 - when the first number changes, THE MAJOR UPDATE!