Mr./Mrs. -san
This is a suffix used after a person’s name when referring to them politely. It can be used with a first or last name. One uses this term only when referring to others and never one’s self.
 
Mr. –kun
This is a diminutive suffix put after a person’s name to which you are senior in age or rank.
 
Teacher…Sensei
It is placed after a person’s name like –san but is used to indicate one’s respect. Sensei can also be used alone when the subject of the sentence is understood by the speakers. It is usually reserved for such people as teachers, artists, authors, and lawyers. It is a relative term and not a rank. One does not become a Sensei upon receiving a black belt.
 
Senior…Senpai
This term, like sensei, is used to indicate the relative superiority of another person. It is also placed after the person’s name or can be used alone. Senpai is not a rank, it is merely a word that recognizes that a person has more seniority at the dojo.
 
*Note: Such ranks as Shihan (master), Hanshi (master), Kyoshi (teacher) Renshi (instructor) and Sosai (organization president or governor) can also be placed after a person’s name when referring to them. Like –san, one never uses these titles when referring to one’s self.
 
NIDAN: Second Level, as in Second Degree Black Belt.
HANSHI: "Master." An honorary title given to the highest Black Belt of an organization, signifying their understanding of their art. In Japan Karate-Do Ryobu-Kai, the Hanshi is the Grandmaster of Ryobu-Kai, Yasuhiro Konishi II.
KOHAI: A student junior to oneself.
KYOSHI: "Knowledgeable person," and usually this title is conferred at rokudan or shichidan, depending on system. I think the most common practice in the large organizations is for this to be at shichidan (7th Dan).
KANCHO: Head instructor at a school.  
RENSHI: "A person who has mastered oneself." This person is considered an expert instructor. This status is prerequisite before attaining the status as KYOSHI. Renshi "has a name." Renshi is no longer one of the many, so to speak. Renshi is usually given at yodan to rokudan, depending on the system.
SENPAI: A senior student.
SENSEI: “One who has gone before” Teacher. It is usually considered proper to address the instructor during practice as "Sensei" rather than by his/her name. If the instructor is a permanent instructor for one's DOJO or for an organization, it is proper to address him/her as "Sensei" off the mat as well.
SHIDOIN: Formally recognized Instructor who has not yet be recognized as a SENSEI. Assistant Instructor.
SHIHAN: A formal title meaning, approximately, "Master instructor." A "teacher of teachers." Hanshi is "wise" or sage-like, hence the common translation of "master."
 
SHIDOIN: Formally recognized Instructor who has not yet be recognized as a SENSEI. Assistant Instructor.
 
YUDANSHU: One who is a black belt.