Java SE 10 (March 2018) introduced type inference for local variables. Java Language Architect Brian Goetz explains the feature.

In the following var examples, it’s not difficult for the reader to logically infer the type of each variable. Furthermore, the contrast between the explicit type declaration and the use of the var ...

Java SE 10 introduced var as the type of a local variable declaration and a lambda formal parameter. The compiler treats var as an identifier with special meaning, but it isn’t considered to be ...

Now we’ll take a closer look. Type erasure is when the Java compiler, at compile-time, removes all generic type information in the code after it has been checked for type correctness.