Reply to Question about transition between songs

Hello!

I'm new to all of this, so I have a couple of questions.. If anyone could help me out I would greately appreciate it!!!

I go to as many electronic music events as I can, and I notied that sometimes DJs use certain effects to transition from one song to the next... sometimes they'll stop the song, but it doesn't stop dry, it kinda echoes a little bit.
Other times there this white noise type of effect in between songs... Im assuming this one is a sample but im not sure.... And lastly, sometimes the do this thing where the song slowly comes stop...

...can anyone tell me how to do these things??? my step up is traktor pro 2 (with an s4)


thank you very much!!