Hi!  I haven't traveled internationally in 10 years, so apologies if this is novice question!
I am traveling from Seattle to Prague, with a 3 hour layover in Amsterdam.
Do I need to go through customs again in Amsterdam?   I will have a carry-on bag with me, so do I need to go through any security again, too?  Or do I just go to the gate to my connecting flight? 
Thanks for any input you can provide! :)