I would like to learn about the vote to close.
As I understand it, it is a moderator who does so.
Does it only take one moderator to make that decision?
Is there a link that shows all the particulars?
As I understand it, it is a moderator who does so.
Any user with at least 3000 reputation points may cast a close (or reopen) vote. On this site, diamond moderators rarely participate in close voting, because the community here is relatively active in close-voting and reviewing, but on other Stack Exchange sites, moderators are more often involved in close voting.
Does it only take one moderator to make that decision?
It only takes one vote by a diamond moderator to close a question. When normal users with close voting privilege cast close votes, 5 such votes are required.
As a special case, users who have earned a gold tag badge in a tag may close questions with that tag as duplicates, or reopen them if they are closed as duplicates.
If the voters choose different close reasons, the reason chosen by the majority takes effect. If an even split occurs, the last vote cast decides the reason, and if a moderator votes, the reason they selected is used regardless of previous voters.
In all cases, closure of a question is reversible. Users with close vote privilege also have reopen vote privilege. 5 votes by such users are required to reopen a question, or 1 vote by a moderator.
Is there a link that shows all the particulars?
This page of the Help Center explains close and reopen vote privilege in detail.