The SDK supports two executables (emulator.exe and SDK.exe). IDEs automatically decide which executable to use
Typically, an IDE that supports MIDlet development automatically uses emulator.exe when it uses the SDK as a device. The emulator.exe conforms to the Universal Emulator Interface (UEI) 1.0.2 specifications.
A MIDlet developer is unlikely to use emulator.exe on the command line, except to start the monitoring of the behavior of a MIDlet. Options that you can use only with emulator.exe are noted in the option listing under CLI options overview. The SDK ignores options and commands that emulator.exe does not support.
The executable SDK.exe supports options and commands that you use in message content development. If you are developing message or browser content, you are more likely to use SDK.exe on the command line. With this executable, you can work within a shell (see Sending repeated commands with a CLI shell) and arrange to have one instance of the SDK send a message to another instance (see Creating and sending an MMS message directly on the SDK).
Options that you can use only with SDK.exe are noted in the option listing under CLI options overview.
Options and commands that SDK.exe does not support cause the entire command to fail, and an error message to be posted.