交流，交际，沟通: whats the difference?
I am sure all three terms can be found in dictionaries, but some of the definitions might overlap and cause new learners confusion, I think it is better to just list their main difference in my answer:

交流 = interact / exchange

交際 = socialize

溝通 = communicate

Examples:


文化交流 (cultural exchange) ; 互相交流 ( interact with each other) 
交際應酬 ( socialize and partying) ；與上流社會交際 (socialize with the upper class ) 
無法溝通 (unable to communicate); 以眼神溝通 ( communicate with looks in the eyes)