Writer’s block – the term is enough to send some writers into shivering shakes and quakes of fear.  But what is it?  This definition, found on the SFWA page, has lots of helpful thoughts and links. 

My feeling is that yes, writers can get a block, of sorts, which gets in the way of their writing.  This seems most likely to happen at a time when they are furthest from their creative center, or extremly worn in body and spirit.  In the shocked time just after the death of a loved one, for instance.

On the other hand, the general “I’m stuck, I can’t seem to write, nothing’s coming to me” block which writers complain of is merely a signal that the writer is:

• Going the wrong direction on a story.  For instance, they may be trying to make a certain plot solution work even though, deep down, they know it’s not believable. 
• Stuck because inspiration has run out.  Now it’s time to brainstorm, but some writers either don’t know how to do this effectivley or are unwilling to put their brain through the mental gymnastics neccessary. 
• Loaded down with expectation, and now cannot goad themselves to the task.  This seems most common when a writer is trying to write in order to fulfill the ‘literary’ expectations of the proffesor., the dreams of their dying mother, or their own lofty concept of what a writer writes.  In this case I think a deep look inside at what the writer has to say would be most helpful.
• Stuck because inspiration has run out.  Did I say that before?  I believe I did, but it bears repeating.  Sometimes the plot has been outlined well, the charactization is good, and the story has the rights tensions-but it’s still hard to write.  Certain things are just not easy to put into words.

Writers write.  If there’s a block in their way, they should write a scene to chisel it away.