Inclusions are non-living substances that may or may not be present in a cell, depending on the cell type. Inclusions are stored nutrients, secretory products, and pigment granules. Examples of inclusions are glycogen

Glycogen

Glycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...

 granules in the liver and muscle cells, lipid

Lipid

Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...

 droplets in fat cells, pigment

Pigment

A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which a material emits light.Many materials selectively absorb...

 granules in certain cells of skin and hair, water containing vacuoles, and crystals of various types.