A tag is a keyword or label that categorizes your question with other, similar questions. Using the right tags makes it easier for others to find and answer your question.
the process of migrating off-topic questions from a Stack Exchange site to another.
referring to the process of identifying and closing questions that are duplicates of another question.
Peer voting on questions and answers gives users most of their reputation, and also usually controls how posts are sorted to the top.
the governing meta site for all Stack Exchange sites together. Use this tag to ask questions about this very site, a.k.a. MSE. In some sense, the [meta] tag is Meta-Meta Stack Exchange.
Real time, stateful web chat that's a part of every Stack Exchange site.
for questions dealing with moderator actions, pages, abilities or decisions.
For questions about the user interface elements (inputs, checkboxes, etc) that make up this site. For questions about the design of elements, use the design tag.
for questions about answers: how to answer, whether specific answers are appropriate, and so forth.
Questions about the various user interface and email elements used to notify users of events on the site.
an editable page that briefly summarizes the topic of the tag and that may provide links to existing questions that are often useful to many people.
for questions regarding the design of the Stack Exchange websites; e.g., for issues with the layout.
a lightweight, plain-text, markup language. It is used across the entire Stack Exchange network for post formatting (Questions, answers, wikis, chat).
for questions specifically about the process of asking questions on a Stack Exchange site.
Questions about sizes and other quantities of Stack Exchange sites, e.g. number of questions, GB/day transferred, etc.
Questions about the user profile page, which contains a list of all the questions, answers, and an audit trail of the user's activity on the site.
refers to all questions deleted from Stack Exchange sites. You can also use this tag along with [specific-question] and [meta] to ask why a specific question on Meta Stack Exchange was delete…
those users who may be new to the Stack Exchange Q&A format, and generally have a low reputation score, which starts from 1 at the time of registration.
for questions about the entire network of Q&A sites that make up the Stack Exchange network.
OpenID was previously the main login flow for Stack Exchange; it has since been deprecated.
currently under consideration, or needs further investigation.
a nonpersonal form of marketing used to promote a service or and idea.
to request the community to consider closed/on hold question(s) for reopening.