J2ME, or Java 2 Platform, Micro Edition, is a technology used for developing applications on mobile devices and embedded systems. It provides a set of tools and libraries that allow developers to create software that can run on various devices, such as mobile phones and PDAs, with limited resources. J2ME is based on the Java programming language and includes a subset of the Java Standard Edition. It features a modular architecture, allowing developers to create applications using MIDP (Mobile Information Device Profile) and CLDC (Connected Limited Device Configuration) to ensure compatibility across different devices and platforms.