hii nilima,
A behavioral interview is a style of interviewing wherein the job applicant is asked to give examples of situations he has personally been involved in where he demonstrated a particular trait or skill that the interviewer is interested in.
A situational interview is a style wherein theoretical or hypothetical situations are given by the interviewer to assess the applicant's behavior in such a situation.
The main difference between behavioral and situational interview is that behavioral interviews focus on past experiences and behavior of the applicant, while situational interviews concentrate on how the applicant will react when confronted with a given situation. These two styles of interviewing are often used in conjunction with each other.
hope this information helps you in uderstanding the type of interview. :D
regards
sravanthi