I'm trying to learn a bit about networking and I'm a little confused about ports. First of all, is there a difference between an open port and a forwarded port? And for a port to be open, does it have to be listening or have an established connection. Second of all, after I typed netstat in cmd, I tried to telnet certain ports on my computer that showed up there and for some of them it gave me a blank screen but it said Telnet xxx.xxx.xxx.xxx on the top so it connected. Why is the screen black, what's going on? For some ports that I tried to connect to it said it could not connect to the host... why couldn't it connect to those ports? Thanks.