This is the second of four sections on lambdas in Java 8. It covers the @FunctionalInterface annotation, method references. lambda scoping rules, and effectively final local variables. See http://www.coreservlets.com/java-8-tutorial/ for the complete tutorial series (Lambdas and Streams in Java 8) and associated code. That site also lets you download PDF files of each lecture, for saving or printing, and includes exercises and exercise solutions.