Nodelets are ROS nodes designed to run multiple algorithms within the same process in an efficient manner. Each process is executed as threads. Threaded nodes communicate efficiently without overloading the network by using zero copy transport between two nodes. Nodelets are used when the volume of data to be transferred between nodes are very high.
sudo apt-get install ros-kinetic-cv-camera
cd ~/{PATH_to_repo}
catkin build
source devel/setup.bash
roslaunch nodelet_webcam nodelet_samp.launch