There could be times that you will need to get the standard output from a script or command in powershell and handle this information. An example that I use is the output of docker info which I use to monitor the service state along with other things. The output of the docker info will inform you about an error during connection if the engine is not working. In the latest version of docker they changed the way message is displayed and this information will be printed on standard error instead of standard output.
As a result when you try to find the connection state through a powershell command you will fail identifying the correct state.
(docker info).Contains('ERROR: error during connect')
This behavior is noticed because the error is printed on standard error.
In order to bypass and get the standard error on the output, you will need to use 2>&1 along with the command.
docker info 2>&1
After that you can handle the output message appropriately.