Thank you for the opportunity to help you with your question!
According to scholars ,the most common definition of terrorism how some people create threat to other innocent people, what is the mentality behind it, who are the mastermind behind it and what are the after effects of these acts on the society.On the other hand the definition of counterterrorism is the practice, tactics ,techniques and strategies that government ,millilaries, police ,departments, co operations adopt in response to terrorists threats and acts , both real and imputed.With the help of all these agencies ,this is the objective of the government of the country to finish this act.
These agencies mission is to neutralize terrorist cell and operatives and to help dismantle terrorist activities worldwide.In USA ,numerous agencies including FBI, CIA, Dept of Homeland Security and the state dept have authority to combat terrorism.So this terrorism should be stopped, lots of loss to the humanity, many innocent people loss their lives, sometimes innocent children loss their lives, that's why it is very important to make these policies for counter terrorism.It is for mankind welfare.
Please let me know if you need any clarification. I'm always happy to answer your questions.