What is the difference between Proverbs/sayings and idioms?

[Gnisy]

And does an idiom have to be long?

[Quizmonster]

Proverbs and sayings are generally short, pithy phrases that reveal some aspect of wisdom (supposedly). "A stitch in time saves nine"..."A rolling stone gathers no moss"..."Don't put all your eggs in one basket" and so on.
An idiom is also generally brief but it is the particular way in which an idea is expressed in a given language. For example, in Britain when it is someone's turn to get a round of drinks in for the company, someome might say "It's your shout." However, nobody in France would say "C''est votre cri", which is the exact translation. No doubt the French have something along the same lines that we would not grasp if it was translated into English.

[Quizmonster]

Just type 'idioms' into the Google search-slot and you will be offered literally millions of suitable websites for examples...'bad hair day'...'pleased as punch'...or whatever.

[Grunty]

I don't think we should worry about that particular idiom - just let the French buy the drinks.

[Gnisy]

Thanks quizmonster. I'm looking for distinction features between them since I can't group the sayings together under proverbs and idioms. If they are named differently, they should have different definitions, right? Or is it just a to-mate-to and to-ma-to thingie?

btw, what is "Call a spade a spade"? an idiom or a proverb, or both?

[Quizmonster]

"Calling a spade a spade" is an idiom. There is no particular 'wisdom' - see my earlier response - involved in saying it, as it is just a way of saying someone is straightforward and uncomplicated.
The element of wisdom about life is what mainly characterises proverbs. That is, hearing them should make you aware of how to tackle life's problems. "Look after the pennies and the pounds will look after themselves" is a proverb advising that the small matters are important and - in terms of money-management - thathe saved pennies will actually rapidly become pounds.
Idioms are just a given language's way of expressing particular ideas in such a way that they cannot be directly, word-for-word, translated into foreign languages. When things go terribly wrong for a Frenchwoman, I'm sure it would never occur to her to say she was having a "mauvais cheveux jour"!! (My French is rusty, so I may have made a mistake there in noun/subject agreement or whatever, but I'm trying to say "bad hair day".)

Does any of that help to differentiate between the two, Gnisy?

[Gnisy]

All I can say is.. thank you so very much Quizmonster. Your last answer made a lot of sense and it helped a lot. Thanks