编程中的“有界”含义

I am trying to follow below presentation

http://www.slideshare.net/borderj/concurrency-in-go-10662038

And I found this statement ,

"typed BOUNDED blocking"

in here what exactly mean by BOUNDED ?

I tried gooling and found that BOUNDED BUFFER explanations but I am looking for more general understanding

It's a loose way to say that channels have an explicit size, and sends block if they're full. By itself "bounded" is not a well-defined term in software development, though.