We use the English idiom ‘It’s the best thing since sliced bread’ to describe something that we think is fantastic or wonderful.
Peter: Can you show me your new phone?
Greta: Here it is.
Peter: Oh, it’s a new iPhone X. These are really amazing. Look at that screen!
Greta: I know. It can do everything – and more! It’s the best thing since sliced bread.
The only question is – what was the best thing before sliced bread was invented?