Q: What are the basic rules of entrusted items?

A: There are four types of shomrim (guardians) for entrusted items: shomer chinam, shomer sachar, socher, and shoel (B.M. 93a).

A shomer chinam is a guardian who does not receive any payment or benefit for his service. He is responsible only for negligence (p’shia), but not for theft or natural loss (C.M. 291:1).

A shomer sachar is a guardian who receives payment or benefit for his service. He is responsible for negligence, theft and natural loss (geneivah va’aveidah), but not for uncontrollable circumstances (303:2-3).

A socher is a guardian who rents an item. He is as responsible for the item as a shomer sachar, i.e. for negligence, theft and natural loss, but not for uncontrollable circumstances (307:1).