Use a .gitignore file to exclude files and directories from the Git version control system.

Multiple .gitignore files can be placed in subdirectories, but it is generally easier to use only one in the root directory, which is where the .git/ directory exists.

# Xcode
build/*
*.pbxuser
*.mode1v3

# Subversion
.svn

# OS X
.DS_Store

# Textmate
*.tmproj