In J2ME, there are three types of configurations:

  1. Connected Limited Device Configuration (CLDC): It is designed for small devices with limited processing power and memory, such as mobile phones, pagers, and personal digital assistants (PDAs). It includes a subset of the Java Class Library and a virtual machine optimized for small devices.

  2. Connected Device Configuration (CDC): It is designed for more powerful devices such as set-top boxes, TV sets, and advanced PDAs. It includes a larger subset of the Java Class Library and a virtual machine optimized for larger devices.

  3. Java SE Embedded: It is designed for embedded systems that require full-featured Java technology. It includes the complete Java Class Library and a virtual machine optimized for embedded systems.

Each of these configurations is designed to meet the requirements of different types of devices, and developers can choose the appropriate configuration for their application depending on the target device's capabilities.