Ex: The contents of a penguin's stomach...
1. Something contained, as in a receptacle. Often used in the plural: the contents of my desk drawer; the contents of an aerosol can.
2. The individual items or topics that are dealt with in a publication or document. Often used in the plural: a table of contents.
3. The substantive or meaningful part: "The brain is hungry not for method but for content, especially content which contains generalizations that are powerful, precise, and explicit" (Frederick Turner).
4. The proportion of a specified substance: Eggs have a high protein content.