Excuse me in the terminal , the response is " Couldn't find executable named talker below /home/ahmed/catkin_ws/src/beginner_tutorials" when I try to carry out the tutorial and type "rosrun beginner_tutorials talker"
Could you help me solving this problem
With the given information, this is difficult (impossible?) to solve. We'll need more information such as CMakeLists.txt to help you out.
Also, try searching with Google before asking because this is a fairly common problem. https://www.google.com/search?q=Could...