Yes, there's a difference between "pass" and "pass out". Generally 'pass' by itself means 'give' to one person or many, whereas 'pass out' means 'distribute', or 'hand out' and it is ALWAYS to several people. So in your example, 'Could you please pass me the salt' = 'Could you please give me the salt'. 'Pass out the cloaks to the people' = 'Distribute/hand out the cloaks to the people (there's more than one)'.

To pass something to someone is to hand it to them. Usually at the dinner table. "Could you pass me the salt?" means... could you hand me the salt so that I don''t have to reach me arm over everyone else who are eating (Its rude) We don't really use "could you pass out the jackets/cloaks" it doesn't feel right. We say "could you hand out the cloaks" - This means to give everyone their cloaks back. Or to give everyone something. Pass out is also used when someone faints - "I'm about to pass out" - this means I'm about to faint/fall asleep. There are many phrasal verbs using pass: Pass by, pass around (same as hand out), pass away, pass on... etc. once I was jet lagged and lay down on the couch. I fell asleep and slept very well. When I woke up I said "Man I passed out!!!" - What I meant was, I was so so so very tired that I fell into the deepest sleep!!