how to tell the difference between adapter for Brazil and continental Europe

Brazil uses what is known as a Type N adapter. Curiously, South Africa uses the same adapter as well. It looks like this:

Most of central Europe uses an Type F adapter, which looks like this:

Amazon has them, or you can pay 3 times as much as the airport shops.

The Brazil adapter (Type N) has three prongs. The Type C, used in much of Europe only has two. But, as Bob noted, parts of Europe use Type F. Where are you going?

My research indicates you can use the Type N in Type C outlets.

https://www.heremagazine.com/articles/global-electrical-plug-guide#:

To be clear, for Apple power adaptors, the ONLY difference is in the physical plug style.

The “inner electrical workings” are all the same worldwide.

A Type C plug should work in Brazil. But, I've run into situations where something that "should" work, doesn't.

Personally, I have not been to Brazil, so can't speak from experience on that one. If I were going to Brazil though, I would spend a few dollars to get the plug adapter that I know will work.

I'm not actually sure if the OP is traveling somewhere or just trying to determine what kind of adapter they currently possess. But, if the pictures we've provided aren't enough, hopefully they will ask.

Yes, having a set of adapters is always recommended!