cannot find -lopencv_highgui [closed]

edit

Compiling cpp using

g++ -std=c++11 decolor.cpp -o fish -I /home/a/Downloads/installation/OpenCV-3.4/include -L /home/a/Downloads/installation/OpenCV-3.4/lib -lopencv_core -lopencv_highgui

fails saying

/usr/bin/ld: cannot find -lopencv_highgui

The command above I copied elsewhere without proper understanding the -lopencv_highgui bit. What is it for?

opencv_highgui is an openCV module. Should it be present as a directory?

command find / -name opencv_highgui

finds nothing

However there is libopencv_highgui in lib directory

Shall I drop -lopencv_highgui from the command or I still need to install opencv_highgu module?