Plz correct me if i am wrong ..?

I want to clear my concept regarding computer science engineering and IT engineering .. To me , IT eng. refers to the utilisation and application of the softwares and hardwares designed by computer science engineers and comp science engineers make the softwares and hardwares required to run a PC ... Now , does an IT professional make softwares , firmwares or hardwares or does he only put those into application .. plz help me because i am having trouble understanding the 2 types of engineering and picking any one to study.... also which has a better future or in other words which would be a better source of income ? ..