what is :(){ :|:& };: command?

'source' is not recognized as an internal or external command, operable program or batch file.

smtp error: password command failed: 535-5.7.8 username and password not accepted.

'choco' is not recognized as an internal or external command, operable program or batch file.

clang: error: linker command failed with exit code 1 (use -v to see invocation)

'pyrcc5' is not recognized as an internal or external command, operable program or batch file

'npm' is not recognized as an internal or external command, operable program or batch file.

'nodemon' is not recognized as an internal or external command, operable program or batch file.

'scriptcs' is not recognized as an internal or external command, operable program or batch file.

'phoenixminer.exe' is not recognized as an internal or external command, operable program or batch file.

command line option 'g' [from -get] is not understood in combination with the other options.