Java, originally named Oak, is a general-purpose, object-oriented programming language developed by Sun Microsystems, designed to improve electronic devices and noted for its portability and reliability. Significant milestones in its development include the release of Java Development Kit (JDK) and Java 2, along with the introduction of features like platform neutrality and multithreading. Today, Java applications are widely used, influencing various sectors such as e-commerce and entertainment, and developers can build software on a single virtual machine for diverse platforms.