What is the difference between Consumer.Fetch.Max and Consumer.Fetch.Default

[sappusaketh]

I have messages in my topic which are > 1MB(Not all but most of them) so I m trying to consume them not seeing any errors from consumer its just stuck but after I configured Consumer.Fetch.Default to 10 MB everything works where as when I configure Consumer.Fetch.Max the same value it doesn't work so my question is what is the difference between them and also Consumer.Fetch.Max default is 0 which it says no limit what does that even mean?