Let's look at the use of the usb_cam package in ROS first. The usb_cam package is the ROS driver for Video4Linux (V4L) USB cameras. V4L is a collection of device drivers in Linux for real-time video capture from webcams. The usb_cam ROS package works using V4L devices and publishes the video stream from devices as ROS image messages. We can subscribe to it and perform our own processing using it. The official ROS page of this package is given in the previous table. You can check out that page for different settings and configurations this package offers.