Chainmaille in General

Chainmaille has been around for about 3,000 years, but some people still think "chain letters" when they hear the term. *grin* 

The "Chainmaille 101" Q&A below provides an overview to this resurging craft as well as a glossary of common terms and abbreviations.

1. What is chainmaille?
2. How many weaves are there?
3. What are some common terms, industry jargon and abbreviations?
4. How is it spelled? Chainmaille? Chain mail? Chainmail?