workspace_folder/ --WORKSPACE

src/ 源空间 --SOURCE SPACE
CMakeLists.txt/ --This is symlinked to catkin/cmake/toplevel.cmake package_1/ CMakeLists.txt package.xml ... package_n/ CMakeLists.txt package.xml

build/ --BUILD SPACE(this is where build system is invoked, not necessarily within workspace)
CATKIN_IGNORE --Marking the folder to be ignored when crawling for packages (necessary when source space is in the root of the workspace, the file is emtpy) 此选项可用于忽略某个包编译

devel/ --DEVEL SPACE (targets go here, parameterizable, but defaults to peer of Build Space)
bin/ 生成二值 库 可执行文件 etc/ include/ lib/ share/ .catkin --Marking the folder as a development space (the file contains a semicolon separated list of Source space paths) env.bash setup.bash setup.sh ...

install/ --INSTALL SPACE (this is where installed targets for test installations go, not necessarily within workspace)
bin/ etc/ include/ lib/ share/ .catkin --Marking the folder as an install space (the file is emtpy) env.bash setup.bash -- Environment setup file for Bash shell setup.sh -- Environment setup file for Bourne shell ...

/opt/ros/groovy/
setup.bash -- Environment setup file for Bash shell setup.sh -- Environment setup file for Bourne shell setup.zsh -- Environment setup file for zshell