Closing a thread means just that. Ending it so no further posts can be made on it.
If you are referring to your foundation question the last post on the thread, made by one of the Board moderators explains that your thread was closed because there is already an existing thread on the same subject, and gives you a link to that thread. It is usual practice for the moderator closing a thread to post on it to explain why it has been closed.
Specktra try to avoid duplicate threads discussing the same question or subject because it helps to keep the resources used by the board, (such as storage and bandwidth - which they have to pay for), to a minimum. This is covered in the Specktra Terms of Service - see item 15 -
http://www.specktra.net/forum/faq.ph...q_specktra_tos