The navigator bar with it's files and folders is so common that almost everyone understands the symbols used. I note the Testing symbols are new to most of us but don't take much getting use to - I love the Lego-styled building block - for components. It's obvious - right - T is for Test.

The real question is what do the Code Sense symbols mean.

These are the symbols that popup while typing code - as Xcode tries to predict some helpful next option for you.

The common symbols:

Class

Structure

Method

Local variable

Property of a type

The Xcode Symbol Navigator (3rd icon from the left) will show you within the context of your own project what many of the symbols mean - pop it open and have a look.

The color coding for these symbols are:

Red - Macros

Brown - Core Data

Orange - Aliased types

Green - Variables / functions

Blue - Methods

Purple - Types

Gray - Code - or code snippets

White - Comments

I've not found a good reference in the Xcode help