A BufferedWriter is a Java class used for writing text to a character output stream efficiently. It uses a buffer to store characters temporarily, which reduces the number of I/O operations by writing larger chunks of data at once. This can significantly improve performance when writing to files or other output destinations. The BufferedWriter is often used in conjunction with other classes, such as FileWriter, to create a more efficient writing process. By wrapping a FileWriter in a BufferedWriter, developers can enhance the speed of file writing while maintaining the simplicity of character-based output.