Subs:

Readers who are totally new need to understand what a "sub" is before we discuss Dom Masters and Protectors.   A submissive or sub is one who chooses to submit to a dominant Master (or Mistress), whom she (or he) will serve and obey.   The word "sub" is commonly used both for one who has a Master and for one who is seeking.     D/s is consensual.   A sub is not subject to any Dom until she has chosen a Master, or a Protector or Trainer.   At that time she and the Dom should discuss the terms and extent of submission and obedience expected.     There are D/s communities in which subs must obey and submit to all Doms.   This is not one of those communities.     Finally, a Sub has a right to a Release from any relationship she finds intolerable.    Occasionally there are Master/slave agreements or contracts with No-Release clauses.    In this community such clauses are considered improper and invalid. Summary:   D/s is consensual.   A sub should observe the community manners and courtesies, but owes obedience only to the Dom of her choosing.

Now we're in a position to discuss Masters Protectors Trainers

But -- and this is IMPORTANT -- what you read here is just the barest introduction.   There's much more to read and learn about these subjects and about D/s.