What is this notation?

[andy12798]

I've been learning a new piece, and I've just come across this // symbol next to a note.
Could someone please tell me what it means?
Thanks

[49410enrique]

it's a Caesura-
 Indicates a brief, silent pause, during which time is not counted. In ensemble playing, time resumes when conductor or leader indicates.

For piano purposes i see them analagous to a grand pause or a breath mark, which essentially do the same thing, only not quite as dramatic.