I had no idea what Java Streams was (a long time since I wrote much Java) and it appears to be the Java version of LINQ:

https://www.foreach.be/blog/java-and-net-comparing-streams-l...

Java streams is the awful copy of LINQ, written something like 7 years later.

LINQ, the IEnumerable extension methods, and IQueryable extension methods.

I'd like to point out that the extension method feature of C# is one big reason why I like this whole story much better than the Streams API in Java. There are often methods I wish were part of the IEnumerable interface, and with extension methods, I can add them myself! (if they are not already provided in, say, MoreLinq [1]). Very convenient, and a big boost in productivity.

https://github.com/morelinq/MoreLINQ

I would say IEnumerable<T> interface.

having a look at it, it seems like LINQ?

linq, kind of, but it has more run time overhead and is more flexible.