Decomposers is another term used for a fungus or other creature that feeds on dead matter.
Many people think that fungi are similar to plants. However, unlike plants, fungi are do not contain chlorophyll. Chlorophyll is the green pigment found in the chloroplasts of plants that captures sunlight energy during photosynthesis. Photosynthesis is the process by which plants use the sunlight energy to convert carbon dioxide and water into oxygen gas and a sugar called glucose. Plants use the glucose that is made during photosynthesis as a food source for energy. Since fungi do not contain the chlorophyll, they cannot photosynthesize. Thus, fungi are heterotrophic (must consume food from another source). Fungi actually digest externally. Their root-like hyphae release digestive enzymes into the soil that break down (digest) dead matter. Once digested, the matter is absorbed through the hyphae.
Without decomposers, organic matter (such as leaves and fallen trees) would build upon the forest floor year after year. Thus, decomposers are natural recyclers of Earth.
Saprophytes are the organisms (including some fungus, bacteria and other microorganisms) that live on dead matter. These organisms break down the complex molecules into simpler ones and then absorb them through endocytosis. For example, proteins are broken down into various amino acids (by the action of enzyme knwon as proteases). Similarly, lipids are broken down into fatty acids bybyhe action of enzyme known as amylases. These organisms may also be termed as detrivores or saprotrophs, etc. An example of such organism is a fungus called as mycorrhizals. This organism survives on the dead matter in a rainforest and competes with the heavy rainfall for the nutrients. These nutrients or simpler molecules then go back into the soil, from where they are reused by plants, thus completing the nutrient cycling.
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