Here are some key points about Java ME:

1. Purpose: Java ME is designed to enable developers to create portable applications for a wide range of embedded and mobile devices. It allows developers to write code once and run it on various Java ME-enabled devices.

2. Profiles and Configurations: Java ME is divided into different configurations and profiles to accommodate different types of devices. The two primary configurations are the Connected Device Configuration (CDC) for more capable devices and the Mobile Information Device Profile (MIDP) for mobile phones and simpler devices.

3. APIs: Java ME provides a subset of Java SE APIs tailored to the constraints of embedded devices. It includes libraries for user interface development, networking, and data storage. MIDP, in particular, has a well-defined set of APIs for mobile application development.

4. CLDC and CDC: The Connected Limited Device Configuration (CLDC) is the foundation for Java ME on low-end devices, while the Connected Device Configuration (CDC) is used for more powerful devices. CDC provides a more extensive set of APIs compared to CLDC.

5. MIDP: The Mobile Information Device Profile (MIDP) is a set of APIs and specifications designed specifically for mobile phones and similar devices. It includes support for user interfaces, networking, and multimedia.

6. Development Tools: Java ME development can be done using various IDEs (Integrated Development Environments) and tools, such as the NetBeans IDE and Eclipse with appropriate plugins. Oracle provides the Java Wireless Toolkit (WTK) for developing Java ME applications.

7. Deployment: Java ME applications are typically deployed as Java Archive (JAR) files, which can be installed and run on Java ME-enabled devices. The installation process may vary depending on the device and its capabilities.

8. Security: Java ME includes security features to protect applications and data on embedded devices. It supports code signing and various security policies.

9. Evolution: While Java ME was popular in the era of feature phones, the mobile landscape has evolved significantly with the rise of smartphones running Android and iOS. Consequently, the use of Java ME has diminished in favor of more modern mobile development platforms.