.minecraft (or simply minecraft in OS X) is the folder Minecraft creates to run from. This folder includes the .jar files, sound, music, resource packs, personal options, worlds, etc.
Locating the .minecraft folder is vital to install several mods as the mod files need to be placed in various folders in .minecraft.
|Mac OS X
If you're a Windows user and are unfamiliar with how to find your appdata folder, follow these steps:
- Click Start → Run. If you don't see "Run" try holding down your "Windows" key and press the R key.
%appdata% (case doesn't matter but be sure to include the
% markers) and click OK.
- Open the
If you're a Linux or Mac user, the
~ in the path refers to your home directory.
 .minecraft hierarchy