Enter a password, choose a cost factor, and generate a bcrypt hash with a built-in random salt that is safe to store in your database.
Bcrypt is deliberately slow and includes a salt, so it resists brute-force and rainbow-table attacks far better than MD5 or SHA.
The work factor (rounds) — each increment doubles the hashing time. 10 to 12 is a common, sensible range.
No — bcrypt embeds the salt and cost inside the hash string, so a single value is all you store.