Suffix - さん - Honorific - Respectful prefix to a name
さん is an honorific suffix attached to someone's name to give respect. It can be used either with males and females, and also with given names and family names. It can also be attached to the name of the occupation and titles. For example: さくらさん (Sakura)
Note that it can never be used when referring to yourself!
It should always be used when talking about people you aren't familiar with. Don't drop the -さん suffix unless you're being specifically invited to.
Note: In more polite situations さま is used instead of さん.