What must match in a method call in Java?

In a method call in Java, it is essential that the number of actual parameters and their types match the formal parameters declared in the method's definition. This ensures that the method is executed correctly with the right data types and the expected number of arguments. If there is a mismatch in either the number of parameters or their types, the Java compiler will raise an error during the compilation process, indicating that the method cannot be found or the arguments provided do not match the expected ones.

This aspect of parameter matching is crucial for effective method execution and helps maintain type safety within the program. It allows the programmer to leverage method overloading, where multiple methods can share the same name but differ in their parameter lists, provided that each method's signature (consisting of its name and parameter types) is unique.