Journal bearings are a type of bearing that supports a rotating shaft, allowing it to turn smoothly with minimal friction. They consist of a cylindrical surface that encases the shaft, typically made from materials like bronze or plastic. The space between the shaft and the bearing is filled with lubricant, which helps reduce wear and heat generated during operation. These bearings are commonly used in various applications, including motors, pumps, and automobiles. Their design allows for easy maintenance and replacement, making them a popular choice in machinery where reliability and efficiency are essential.