Library /sys$common/syshlp/decw$helphelp.hlb Glossary, Visit  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  To Visit a topic means to leave the current topic open
  in its window, and open an additional window to display
  the requested new topic.

  This is to be compared to Go To Topic, where the current
  topic window is closed, and the new topic replaces it.