What is the difference between probable clause and reasonable doubt?

In short, probable cause requires the belief of the affiant that more likely than not these are the facts of the situation, whereas, beyond a reasonable doubt is a higher standard of proof which would require a standard that there is no doubt (reasonably) that these are the facts of the situation.

Probable cause is used for making an arrest, obtaining warrants, etc... where beyond a reasonable doubt is used during the criminal justice trial by the jury/judge for convictions of the crimes being charged.