Understanding syntax of output from alias

I don't understand how to read the string and the escaping of the following output from listing aliases

> alias foo="echo 'hello'"
> alias
...
alias foo='echo '\''hello'\'''
...

It doesn't make sense to me because '\' should be a string, then 'hello', but then there would be \' an escaped single quote, and then an unmatched single quote ' Probably '\'' is supposed to be just a string with an escaped ', but I thought single quotes cannot appear within single quoted strings, it will just be interpreted as the end quote