Original: Most edible eggs, including bird eggs and turtle eggs, consist of a protective, oval eggshell, the albumen (egg white), the vitellus (egg yolk), and various thin membranes.
Simplified: Most eggs that are eaten by humans, including birds' eggs and turtle's eggs, have a protective, oval eggshell, the albumen (egg white), the vitellus (egg yolk), and various thin membranes, that are layers like skin.